Concentration and size dependence of peak wavelength shift on quantum dots in colloidal suspension

Science.gov (United States)

Rinehart, Benjamin S.; Cao, Caroline G. L.

2016-08-01

Quantum dots (QDs) are semiconductor nanocrystals that have significant advantages over organic fluorophores, including their extremely narrow Gaussian emission bands and broad absorption bands. Thus, QDs have a wide range of potential applications, such as in quantum computing, photovoltaic cells, biological sensing, and electronics. For these applications, aliasing provides a detrimental effect on signal identification efficiency. This can be avoided through characterization of the QD fluorescence signals. Characterization of the emissivity of CdTe QDs as a function of concentration (1 to 10 mg/ml aqueous) was conducted on 12 commercially available CdTe QDs (emission peaks 550 to 730 nm). The samples were excited by a 50-mW 405-nm laser with emission collected via a free-space CCD spectrometer. All QDs showed a redshift effect as concentration increased. On average, the CdTe QDs exhibited a maximum shift of +35.6 nm at 10 mg/ml and a minimum shift of +27.24 nm at 1 mg/ml, indicating a concentration dependence for shift magnitude. The concentration-dependent redshift function can be used to predict emission response as QD concentration is changed in a complex system.

Pre-"peak water" time in the southwest Yukon: when cryospheric changes trigger hydrological regime shifts

Science.gov (United States)

Baraer, M.; Chesnokova, A.; Huh, K. I.; Laperriere-Robillard, T.

2017-12-01

Saint-Elias Mountains host numerous cryospheric systems such as glaciers, seasonal and perennial snow cover, permafrost, aufeis, and different forms of buried ice. Those systems are very sensitive to climate changes and exhibit ongoing reduction in extent and/or changes in formation/ablation times. Because they highly influence the hydrological regimes of rivers, cryospheric changes raise concerns about consequences for regional water resources and ecosystems. The present study combines historical data analysis and hydrological modeling in order to estimate how cryospheric changes impact hydrological regimes at eight watersheds of different glacier cover (0- 30%) in the southwest Yukon. Methods combine traditional hydrograph analysis techniques and more advance techniques such as Fast Fourier Transform filters used to isolate significant trends in discharge properties from noise or climatic oscillations. Measured trends in discharge variables are connected to cryospheric changes by using a water balance / peak water model (Baraer et al., 2012), here adapted to the main cryospheric systems that characterize the southwest Yukon.Results show three distinct hydrological regimes for (1) non glacierized, (2) glacierized, and (3) major lakes hosting catchments. The studied glacierized catchments have not passed the "peak water" yet and still exhibit increases in yearly and late summer discharges and a decrease in runoff variability. All watersheds show an increase in winter discharge and a snowmelt-driven shift of yearly peak discharge toward earlier in the season. The study suggests that, in a couple of decades, water resources and dependent ecosystems will face the combined effects of (A) a shift in the contribution trend from declining perennial cryospheric systems and (B) continuing alteration of the contribution from the seasonal cryospheric systems.

Kondo peak splitting and Kondo dip in single molecular magnet junctions

Energy Technology Data Exchange (ETDEWEB)

Niu, Pengbin, E-mail: 120233951@qq.com [Institute of Solid State Physics, Shanxi Datong University, Datong 037009 (China); Shi, Yunlong; Sun, Zhu [Institute of Solid State Physics, Shanxi Datong University, Datong 037009 (China); Nie, Yi-Hang [Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China); Luo, Hong-Gang [Center for Interdisciplinary Studies & Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000 (China); Beijing Computational Science Research Center, Beijing 100084 (China)

2016-01-15

Many factors containing bias, spin–orbit coupling, magnetic fields applied, and so on can strongly influence the Kondo effect, and one of the consequences is Kondo peak splitting (KPS). It is natural that KPS should also appear when another spin degree of freedom is involved. In this work we study the KPS effects of single molecular magnets (SMM) coupled with two metallic leads in low-temperature regime. It is found that the Kondo transport properties are strongly influenced by the exchange coupling and anisotropy of the magnetic core. By employing Green's function method in Hubbard operator representation, we give an analytical expression for local retarded Green's function of SMM and discussed its low-temperature transport properties. We find that the anisotropy term behaves as a magnetic field and the splitting behavior of exchange coupling is quite similar to the spin–orbit coupling. These splitting behaviors are explained by introducing inter-level or intra-level transitions, which account for the seven-peak splitting structure. Moreover, we find a Kondo dip at Fermi level under proper parameters. These Kondo peak splitting behaviors in SMM deepen our understanding to Kondo physics and should be observed in the future experiments. - Highlights: • We study Kondo peak splitting in single molecular magnets. • We study Kondo effect by Hubbard operator Green's function method. • We find Kondo peak splitting structures and a Kondo dip at Fermi level. • The exchange coupling and magnetic anisotropy induce fine splitting structure. • The splitting structures are explained by inter-level or intra-level transitions.

Implementing peak load reduction algorithms for household electrical appliances

International Nuclear Information System (INIS)

Dlamini, Ndumiso G.; Cromieres, Fabien

2012-01-01

Considering household appliance automation for reduction of household peak power demand, this study explored aspects of the interaction between household automation technology and human behaviour. Given a programmable household appliance switching system, and user-reported appliance use times, we simulated the load reduction effectiveness of three types of algorithms, which were applied at both the single household level and across all 30 households. All three algorithms effected significant load reductions, while the least-to-highest potential user inconvenience ranking was: coordinating the timing of frequent intermittent loads (algorithm 2); moving period-of-day time-flexible loads to off-peak times (algorithm 1); and applying short-term time delays to avoid high peaks (algorithm 3) (least accommodating). Peak reduction was facilitated by load interruptibility, time of use flexibility and the willingness of users to forgo impulsive appliance use. We conclude that a general factor determining the ability to shift the load due to a particular appliance is the time-buffering between the service delivered and the power demand of an appliance. Time-buffering can be ‘technologically inherent’, due to human habits, or realised by managing user expectations. There are implications for the design of appliances and home automation systems. - Highlights: ► We explored the interaction between appliance automation and human behaviour. ► There is potential for considerable load shifting of household appliances. ► Load shifting for load reduction is eased with increased time buffering. ► Design, human habits and user expectations all influence time buffering. ► Certain automation and appliance design features can facilitate load shifting.

Effect of Co-60 single escape peak on detection of Cs-137 in analysis of radionuclide from research reactor

International Nuclear Information System (INIS)

Kim, M. S.; Park, S. J.

2006-01-01

The effect of the single escape peak of 1173 keV gamma-rays from Co-60 on the detection of Cs-137 activity is analyzed. The single escape peak of 1173 keV gamma-rays from Co-60 is located at the 662 keV, which is very close to the energy of gamma-rays from Cs-137. This single escape peak may be mistaken for the gamma-ray peak from Cs-137 activity in the case of large area of 1173 keV peak. The detection of Cs-137 is very important to the judgment of the contamination or the leakage of the material containing the fission product like reactor pool water and in the several experiments for reactor physics such as burn-up estimation. In this work, the areas of the single escape peak of the 1173 keV gamma-rays from Co-60 are measured with several full energy peak areas by using the HPGe detector. The critical limit by which we can decide whether the net count of 662 keV peak due to Co-60 would be significant or not is deduced. For this detection system, when the area of full energy peak is larger than 4.5 million, the single escape peak of 1173 keV gamma-rays from Co-60 can be regarded as the single significant peak. Therefore, it is confirmed that the detection of the Cs-137 activity is affected by the Co-60 in this case. Conservatively, for this detection system, it is recommended that the area of 1173 keV peak of Co-60 would be less than 2 million for neglecting the effect of Co-60. (authors)

Ocular Measures of Sleepiness Are Increased in Night Shift Workers Undergoing a Simulated Night Shift Near the Peak Time of the 6-Sulfatoxymelatonin Rhythm

Science.gov (United States)

Ftouni, Suzanne; Sletten, Tracey L.; Nicholas, Christian L.; Kennaway, David J.; Lockley, Steven W.; Rajaratnam, Shantha M.W.

2015-01-01

Study Objectives: The study examined the relationship between the circadian rhythm of 6-sulphatoxymelatonin (aMT6s) and ocular measures of sleepiness and neurobehavioral performance in shift workers undergoing a simulated night shift. Methods: Twenty-two shift workers (mean age 33.4, SD 11.8 years) were tested at approximately the beginning (20:00) and the end (05:55) of a simulated night shift in the laboratory. At the time point corresponding to the end of the simulated shift, 14 participants were classified as being within range of 6-sulphatoxymelatonin (aMT6s) acrophase— defined as 3 hours before or after aMT6s peak—and 8 were classified as outside aMT6s acrophase range. Participants completed the Karolinska Sleepiness Scale (KSS) and the auditory psychomotor vigilance task (aPVT). Waking electroencephalography (EEG) was recorded and infrared reflectance oculography was used to collect ocular measures of sleepiness: positive and negative amplitude/velocity ratio (PosAVR, NegAVR), mean blink total duration (BTD), the percentage of eye closure (%TEC), and a composite score of sleepiness levels (Johns Drowsiness Scale; JDS). Results: Participants who were tested within aMT6s acrophase range displayed higher levels of sleepiness on ocular measures (%TEC, BTD, PosAVR, JDS), objective sleepiness (EEG delta power frequency band), subjective ratings of sleepiness, and neurobehavioral performance, compared to those who were outside aMT6s acrophase range. Conclusions: The study demonstrated that objective ocular measures of sleepiness are sensitive to circadian rhythm misalignment in shift workers. Citation: Ftouni S, Sletten TL, Nicholas CL, Kennaway DJ, Lockley SW, Rajaratnam SM. Ocular measures of sleepiness are increased in night shift workers undergoing a simulated night shift near the peak time of the 6-sulfatoxymelatonin rhythm. J Clin Sleep Med 2015;11(10):1131–1141. PMID:26094925

Improvement of Bragg peak shift estimation using dimensionality reduction techniques and predictive linear modeling

Science.gov (United States)

Xing, Yafei; Macq, Benoit

2017-11-01

With the emergence of clinical prototypes and first patient acquisitions for proton therapy, the research on prompt gamma imaging is aiming at making most use of the prompt gamma data for in vivo estimation of any shift from expected Bragg peak (BP). The simple problem of matching the measured prompt gamma profile of each pencil beam with a reference simulation from the treatment plan is actually made complex by uncertainties which can translate into distortions during treatment. We will illustrate this challenge and demonstrate the robustness of a predictive linear model we proposed for BP shift estimation based on principal component analysis (PCA) method. It considered the first clinical knife-edge slit camera design in use with anthropomorphic phantom CT data. Particularly, 4115 error scenarios were simulated for the learning model. PCA was applied to the training input randomly chosen from 500 scenarios for eliminating data collinearities. A total variance of 99.95% was used for representing the testing input from 3615 scenarios. This model improved the BP shift estimation by an average of 63+/-19% in a range between -2.5% and 86%, comparing to our previous profile shift (PS) method. The robustness of our method was demonstrated by a comparative study conducted by applying 1000 times Poisson noise to each profile. 67% cases obtained by the learning model had lower prediction errors than those obtained by PS method. The estimation accuracy ranged between 0.31 +/- 0.22 mm and 1.84 +/- 8.98 mm for the learning model, while for PS method it ranged between 0.3 +/- 0.25 mm and 20.71 +/- 8.38 mm.

Shifting of the electron-capture-to-the-continuum peak in proton-helium collisions at 10 and 20 keV

International Nuclear Information System (INIS)

Bhattacharya, S.; Deb, N.C.; Roy, K.; Sahoo, S.; Crothers, D.S.F.

2005-01-01

A refined theoretical approach has been developed to study the double-differential cross sections (DDCS's) in proton-helium collisions as a function of the ratio of ionized electron velocity to the incident proton velocity. The refinement is done in the present coupled-channel calculation by introducing a continuum distorted wave in the final state coupled with discrete states including direct as well as charge transfer channels. It is confirmed that the electron-capture-to-the-continuum (ECC) peak is slightly shifted to a lower electron velocity than the equivelocity position. Comparing measurements and classical trajectory Monte Carlo (CTMC) calculations at 10 and 20 keV proton energies, excellent agreement of the ECC peak heights is achieved at both energies. However, a minor disagreement in the peak positions between the present calculation and the CTMC results is noted. A smooth behavior of the DDCS is found in the present calculation on both sides of the peak whereas the CTMC results show some oscillatory behavior particularly to the left of the peak, associated with the statistical nature of CTMC calculations

Ultrasonic Transducer Peak-to-Peak Optical Measurement

Directory of Open Access Journals (Sweden)

Pavel Skarvada

2012-01-01

Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

The shifting nature of vegetation controls on peak snowpack with varying slope and aspect

Science.gov (United States)

Biederman, J. A.; Harpold, A. A.; Broxton, P. D.; Brooks, P. D.

2012-12-01

The controls on peak seasonal snowpack are known to shift between forested and open environments as well as with slope and aspect. Peak snowpack is predicted well by interception models under uniformly dense canopy, while topography, wind and radiation are strong predictors in open areas. However, many basins have complex mosaics of forest canopy and small gaps, where snowpack controls involve complex interactions among climate, topography and forest structure. In this presentation we use a new fully distributed tree-scale model to investigate vegetation controls on snowpack for a range of slope and aspect, and we evaluate the energy balance in forest canopy and gap environments. The model is informed by airborne LiDAR and ground-based observations of climate, vegetation and snowpack. It represents interception, snow distribution by wind, latent and sensible heat fluxes, and radiative fluxes above and below the canopy at a grid scale of 1 m square on an hourly time step. First, the model is minimally calibrated using continuous records of snow depth and snow water equivalent (SWE). Next, the model is evaluated using distributed observations at peak accumulation. Finally, the domain is synthetically altered to introduce ranges of slope and aspect. Northerly aspects accumulate greater peak SWE than southerly aspects (e.g. 275 mm vs. 250 mm at a slope of 28 %) but show lower spatial variability (e. g. CV = 0.14 vs. CV = 0.17 at slope of 28 %). On northerly aspects, most of the snowpack remains shaded by vegetation, whereas on southerly aspects the northern portions of gaps and southern forest edges receive direct insolation during late winter. This difference in net radiation makes peak SWE in forest gaps and adjacent forest edges more sensitive to topography than SWE in areas under dense canopy. Tree-scale modeling of snow dynamics over synthetic terrain offers extensive possibilities to test interactions among vegetation and topographic controls.

A single-gradient junction technique to replace multiple-junction shifts for craniospinal irradiation treatment

International Nuclear Information System (INIS)

Hadley, Austin; Ding, George X.

2014-01-01

Craniospinal irradiation (CSI) requires abutting fields at the cervical spine. Junction shifts are conventionally used to prevent setup error–induced overdosage/underdosage from occurring at the same location. This study compared the dosimetric differences at the cranial-spinal junction between a single-gradient junction technique and conventional multiple-junction shifts and evaluated the effect of setup errors on the dose distributions between both techniques for a treatment course and single fraction. Conventionally, 2 lateral brain fields and a posterior spine field(s) are used for CSI with weekly 1-cm junction shifts. We retrospectively replanned 4 CSI patients using a single-gradient junction between the lateral brain fields and the posterior spine field. The fields were extended to allow a minimum 3-cm field overlap. The dose gradient at the junction was achieved using dose painting and intensity-modulated radiation therapy planning. The effect of positioning setup errors on the dose distributions for both techniques was simulated by applying shifts of ± 3 and 5 mm. The resulting cervical spine doses across the field junction for both techniques were calculated and compared. Dose profiles were obtained for both a single fraction and entire treatment course to include the effects of the conventional weekly junction shifts. Compared with the conventional technique, the gradient-dose technique resulted in higher dose uniformity and conformity to the target volumes, lower organ at risk (OAR) mean and maximum doses, and diminished hot spots from systematic positioning errors over the course of treatment. Single-fraction hot and cold spots were improved for the gradient-dose technique. The single-gradient junction technique provides improved conformity, dose uniformity, diminished hot spots, lower OAR mean and maximum dose, and one plan for the entire treatment course, which reduces the potential human error associated with conventional 4-shifted plans

Evidence for a peak shift in a humoral response to helminths: age profiles of IgE in the Shuar of Ecuador, the Tsimane of Bolivia, and the U.S. NHANES.

Directory of Open Access Journals (Sweden)

Aaron D Blackwell

2011-06-01

Full Text Available The peak shift model predicts that the age-profile of a pathogen's prevalence depends upon its transmission rate, peaking earlier in populations with higher transmission and declining as partial immunity is acquired. Helminth infections are associated with increased immunoglobulin E (IgE, which may convey partial immunity and influence the peak shift. Although studies have noted peak shifts in helminths, corresponding peak shifts in total IgE have not been investigated, nor has the age-patterning been carefully examined across populations. We test for differences in the age-patterning of IgE between two South American forager-horticulturalist populations and the United States: the Tsimane of Bolivia (n=832, the Shuar of Ecuador (n=289, and the U.S. NHANES (n=8,336. We then examine the relationship between total IgE and helminth prevalences in the Tsimane.Total IgE levels were assessed in serum and dried blood spots and age-patterns examined with non-linear regression models. Tsimane had the highest IgE (geometric mean =8,182 IU/ml, followed by Shuar (1,252 IU/ml, and NHANES (52 IU/ml. Consistent with predictions, higher population IgE was associated with steeper increases at early ages and earlier peaks: Tsimane IgE peaked at 7 years, Shuar at 10 years, and NHANES at 17 years. For Tsimane, the age-pattern was compared with fecal helminth prevalences. Overall, 57% had detectable eggs or larva, with hookworm (45.4% and Ascaris lumbricoides (19.9% the most prevalent. The peak in total IgE occurred around the peak in A. lumbricoides, which was associated with higher IgE in children <10, but with lower IgE in adolescents.The age-patterning suggests a peak shift in total IgE similar to that seen in helminth infections, particularly A. lumbricoides. This age-patterning may have implications for understanding the effects of helminths on other health outcomes, such as allergy, growth, and response to childhood vaccination.

Evidence for a peak shift in a humoral response to helminths: age profiles of IgE in the Shuar of Ecuador, the Tsimane of Bolivia, and the U.S. NHANES.

Science.gov (United States)

Blackwell, Aaron D; Gurven, Michael D; Sugiyama, Lawrence S; Madimenos, Felicia C; Liebert, Melissa A; Martin, Melanie A; Kaplan, Hillard S; Snodgrass, J Josh

2011-06-01

The peak shift model predicts that the age-profile of a pathogen's prevalence depends upon its transmission rate, peaking earlier in populations with higher transmission and declining as partial immunity is acquired. Helminth infections are associated with increased immunoglobulin E (IgE), which may convey partial immunity and influence the peak shift. Although studies have noted peak shifts in helminths, corresponding peak shifts in total IgE have not been investigated, nor has the age-patterning been carefully examined across populations. We test for differences in the age-patterning of IgE between two South American forager-horticulturalist populations and the United States: the Tsimane of Bolivia (n=832), the Shuar of Ecuador (n=289), and the U.S. NHANES (n=8,336). We then examine the relationship between total IgE and helminth prevalences in the Tsimane. Total IgE levels were assessed in serum and dried blood spots and age-patterns examined with non-linear regression models. Tsimane had the highest IgE (geometric mean =8,182 IU/ml), followed by Shuar (1,252 IU/ml), and NHANES (52 IU/ml). Consistent with predictions, higher population IgE was associated with steeper increases at early ages and earlier peaks: Tsimane IgE peaked at 7 years, Shuar at 10 years, and NHANES at 17 years. For Tsimane, the age-pattern was compared with fecal helminth prevalences. Overall, 57% had detectable eggs or larva, with hookworm (45.4%) and Ascaris lumbricoides (19.9%) the most prevalent. The peak in total IgE occurred around the peak in A. lumbricoides, which was associated with higher IgE in children <10, but with lower IgE in adolescents. The age-patterning suggests a peak shift in total IgE similar to that seen in helminth infections, particularly A. lumbricoides. This age-patterning may have implications for understanding the effects of helminths on other health outcomes, such as allergy, growth, and response to childhood vaccination.

Simulating double-peak hydrographs from single storms over mixed-use watersheds

Science.gov (United States)

Yang Yang; Theodore A. Endreny; David J. Nowak

2015-01-01

Two-peak hydrographs after a single rain event are observed in watersheds and storms with distinct volumes contributing as fast and slow runoff. The authors developed a hydrograph model able to quantify these separate runoff volumes to help in estimation of runoff processes and residence times used by watershed managers. The model uses parallel application of two...

Optical π phase shift created with a single-photon pulse.

Science.gov (United States)

Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan

2016-04-01

A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.

Similarities in the dynamical behavior across the classical peak effect and the second magnetization peak in single crystals of 2H-NbSe2

International Nuclear Information System (INIS)

Thakur, A.D.; Ramakrishnan, S.; Grover, A.K.; Chandrasekhar Rao, T.V.; Uji, S.; Terashima, T.; Higgins, M.J.

2005-01-01

The classical peak effect (CPE) and the second magnetization peak (SMP) are two distinct anomalies in critical current of superconductors. A nascent pinned single crystal sample of 2HNbSe 2 (T c (0) ∼7.2 K) shows only the sharp CPE. In a moderately pinned sample (T c (0) ∼6 K), the sharp CPE broadens with the addition of characteristic structure (stepwise amorphization) between the onset and the peak positions of the CPE. Also, there emerges another anomalous peak akin to SMP prior to the CPE. We have looked at samples of 2H-NbSe 2 with intermediate levels of quenched random pinning (T c (0) ∼ 7.1 K) and successfully explored the two peaks down to 50 mK. (author)

Peak effect and vortex dynamics in superconducting MgB2 single crystals

International Nuclear Information System (INIS)

Lee, Hyun-Sook; Jang, Dong-Jin; Kim, Heon-Jung; Kang, Byeongwon; Lee, Sung-Ik

2007-01-01

The dynamic nature of the vortex state of MgB 2 single crystals near the peak effect (PE) region, which is very different either from that of conventional low-temperature superconductors or from that of high-temperature cuprate superconductors, is introduced in this article. Relaxation from a disordered, metastable field-cooled (FC) state to an ordered, stable zero-field-cooled (ZFC) state of the MgB 2 single crystals under an applied magnetic field and current is investigated. From an analysis of the noise properties in the ZFC state, a dynamic vortex phase diagram of the MgB 2 is obtained near the PE region. Between the onset and the peak region in the critical current vs. magnetic field diagram, crossovers from a high-noise state to a noise-free state are observed with increasing current. Above the peak, however, an opposite phenomenon, crossovers from a noise-free to a high-noise state, is observed which has not been observed in any other superconductors. The hysteresis in the I-V curves and the two-level random telegraph noise in the time evolution of the voltage response under an constant applied current at the ZFC state are also studied in detail

Algorithms for image recovery calculation in extended single-shot phase-shifting digital holography

Science.gov (United States)

Hasegawa, Shin-ya; Hirata, Ryo

2018-04-01

The single-shot phase-shifting method of image recovery using an inclined reference wave has the advantages of reducing the effects of vibration, being capable of operating in real time, and affording low-cost sensing. In this method, relatively low reference angles compared with that in the conventional method using phase shift between three or four pixels has been required. We propose an extended single-shot phase-shifting technique which uses the multiple-step phase-shifting algorithm and the corresponding multiple pixels which are the same as that of the period of an interference fringe. We have verified the theory underlying this recovery method by means of Fourier spectral analysis and its effectiveness by evaluating the visibility of the image using a high-resolution pattern. Finally, we have demonstrated high-contrast image recovery experimentally using a resolution chart. This method can be used in a variety of applications such as color holographic interferometry.

Automated Peak Picking and Peak Integration in Macromolecular NMR Spectra Using AUTOPSY

Science.gov (United States)

Koradi, Reto; Billeter, Martin; Engeli, Max; Güntert, Peter; Wüthrich, Kurt

1998-12-01

A new approach for automated peak picking of multidimensional protein NMR spectra with strong overlap is introduced, which makes use of the program AUTOPSY (automatedpeak picking for NMRspectroscopy). The main elements of this program are a novel function for local noise level calculation, the use of symmetry considerations, and the use of lineshapes extracted from well-separated peaks for resolving groups of strongly overlapping peaks. The algorithm generates peak lists with precise chemical shift and integral intensities, and a reliability measure for the recognition of each peak. The results of automated peak picking of NOESY spectra with AUTOPSY were tested in combination with the combined automated NOESY cross peak assignment and structure calculation routine NOAH implemented in the program DYANA. The quality of the resulting structures was found to be comparable with those from corresponding data obtained with manual peak picking.

Prediction of peak overlap in NMR spectra

International Nuclear Information System (INIS)

Hefke, Frederik; Schmucki, Roland; Güntert, Peter

2013-01-01

Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

Gamma-ray escape peak characteristics of radiation-damaged reverse-electrode germanium coaxial detectors

International Nuclear Information System (INIS)

Pehl, R.H.; Hull, E.L.; Madden, N.W.; Xing Jingshu; Friesel, D.L.

1996-01-01

A comparison of the characteristics of full-energy gamma-ray peaks and their corresponding escape peaks when high energy photons interact in radiation damaged reverse-electrode (n-type) germanium coaxial detectors is presented. Coaxial detector geometry is the dominant factor, causing charge collection to be dramatically better for interactions occurring near the outer periphery of the detector as well as increasing of the probability of escape events occurring in this region. It follows that the resolution of escape peaks is better than that of ordinary gamma-ray peaks. This is experimentally verified. A nearly identical but undamaged detector exhibited significant Doppler broadening of single escape peaks. Because double escape events preferentially occur at outer radii, energy shifts of double escape reflect extremely small amounts of charge trapping in undamaged detectors. (orig.)

MRS of pilocytic astrocytoma: The peak at 2 ppm may not be NAA.

Science.gov (United States)

Tamrazi, Benita; Nelson, Marvin D; Blüml, Stefan

2017-08-01

To determine whether the chemical shift of residual N-acetylaspartate (NAA) signal in pilocytic astrocytomas (PA) is consistent with the position of the NAA peak in controls. MR spectra from 27 pediatric World Health Organization (WHO) grade I pilocytic astrocytoma patients, fifteen patients with WHO grade II and high-grade (III-IV) astrocytomas, and 36 controls were analyzed. All spectra were acquired with a short echo time (35 ms), single voxel point-resolved spectroscopy sequence on clinical 3 tesla scanners. Fully automated LCModel software was used for processing, which included the fitting of peak positions for NAA and creatine (Cr). The chemical shift difference between the NAA and Cr peaks was significantly smaller (by 0.016 ± 0.005 parts per million, P NAA peak in PAs is not consistent with NAA. The signal likely originates from an N-acetyl group of one or more other chemicals such as N-acetylated sugars. Magn Reson Med 78:452-456, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Peak effect in untwinned YBa 2Cu 3O 7-δ single crystals

Science.gov (United States)

D'Anna, G.; André, M.-O.; Indenbom, M. V.; Benoit, W.

1994-12-01

We report on the observation of a weak effect of the critical current density in untwinned YBa 2Cu 3O 7-δ single crystals of different purity, using a low frequency torsion pendulum. We construct the peak effect line and the irreversibility line.

Shift of localized surface plasmon resonance by Ar-ion irradiation of Ag–Au bimetallic films deposited on Al{sub 2}O{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Meng, Xuan [Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Shibayama, Tamaki, E-mail: shiba@qe.eng.hokudai.ac.jp [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Yu, Ruixuan; Takayanagi, Shinya [Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Watanabe, Seiichi [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

2013-11-01

Effects of Ar-ion induced surface nanostructuring were studied using 100 keV Ar-ion irradiation of 30 nm Ag–Au bimetallic films deposited on Al{sub 2}O{sub 3} single crystals, under irradiation fluences ranging from 5.0 × 10{sup 15} cm{sup −2} to 6.3 × 10{sup 16} cm{sup −2}. Scanning electron microscope was used to study the ion-beam-induced surface nanostructuring. As the irradiation fluence increased, dewetting of the bimetallic films on the Al{sub 2}O{sub 3} substrate was observed, and formation of isolated Ag–Au nanostructures sustained on the substrate were obtained. Next, thermal annealing was performed under high vacuum at 1073 K for 2 h; a layer of photosensitive Ag–Au alloy nanoballs partially embedded in the Al{sub 2}O{sub 3} substrate was obtained when higher fluence irradiation (>3.8 × 10{sup 16} cm{sup −2}) was used. The microstructures of the nanoballs were investigated using a transmission electron microscope, and the nanoballs were found to be single crystals with a FCC structure. In addition, photoabsorption spectra were measured, and localized surface plasmon resonance peaks were observed. With increase in the irradiation fluence, the size of the Ag–Au nanoballs on the substrate decreased, and a blue-shift of the LSPR peaks was observed. Further control of the LSPR frequency over a wide range was achieved by modifying the chemical components, and a red-shift of the LSPR peaks was observed as the Au concentration increased. In summary, ion irradiation is an effective approach toward surface nanostructuring, and the nanocomposites obtained have potential applications in optical devices.

A new approach for white organic light-emitting diodes of single emitting layer using large stokes shift.

Science.gov (United States)

Kim, Beomjin; Park, Youngil; Kim, Seungho; Lee, Younggu; Park, Jongwook

2014-08-01

DPPZ showed UV-Vis. and PL maximum values of 412 and 638 nm, meaning the large stokes shift. Blue host compound, TAT was synthesized and used for co-mixed white emission. TAT exhibited UV-Vis. and PL maximum values of 403 nm and 445 nm in film state. Thus, when two compounds are used as co-mixed emitter in OLED device, there is no energy transfer from blue emission of TAT to DPPZ due to large stokes shift of DPPZ. Based on the PL result, it is available to realize two-colored white in PL and EL spectra. As a result of this, two-mixed compounds showed vivid their own PL emission peaks of 449 and 631 nm in film state. Also, white OLED device using two-mixed compounds system was fabricated. EL spectrum shows 457 and 634 nm peaks and two separate EL peaks, respectively. As the operation voltage is increased from 7 to 11 V, EL spectrum does not change the peak shape and maximum wavelength values. EL performance of white device showed 0.29 cd/A, 0.14 lm/W, and CIE (0.325, 0.195) at 7 V.

Detecting cm-scale hot spot over 24-km-long single-mode fiber by using differential pulse pair BOTDA based on double-peak spectrum.

Science.gov (United States)

Diakaridia, Sanogo; Pan, Yue; Xu, Pengbai; Zhou, Dengwang; Wang, Benzhang; Teng, Lei; Lu, Zhiwei; Ba, Dexin; Dong, Yongkang

2017-07-24

In distributed Brillouin optical fiber sensor when the length of the perturbation to be detected is much smaller than the spatial resolution that is defined by the pulse width, the measured Brillouin gain spectrum (BGS) experiences two or multiple peaks. In this work, we propose and demonstrate a technique using differential pulse pair Brillouin optical time-domain analysis (DPP-BOTDA) based on double-peak BGS to enhance small-scale events detection capability, where two types of single mode fiber (main fiber and secondary fiber) with 116 MHz Brillouin frequency shift (BFS) difference have been used. We have realized detection of a 5-cm hot spot at the far end of 24-km single mode fiber by employing a 50-cm spatial resolution DPP-BOTDA with only 1GS/s sampling rate (corresponding to 10 cm/point). The BFS at the far end of 24-km sensing fiber has been measured with 0.54 MHz standard deviation which corresponds to a 0.5°C temperature accuracy. This technique is simple and cost effective because it is implemented using the similar experimental setup of the standard BOTDA, however, it should be noted that the consecutive small-scale events have to be separated by a minimum length corresponding to the spatial resolution defined by the pulse width difference.

Surface potential measurement of insulators in negative-ion implantation by secondary electron energy-peak shift

International Nuclear Information System (INIS)

Nagumo, Shoji; Toyota, Yoshitaka; Tsuji, Hiroshi; Gotoh, Yasuhito; Ishikawa, Junzo; Sakai, Shigeki; Tanjyo, Masayasu; Matsuda, Kohji.

1993-01-01

Negative-ion implantation is expected to realize charge-up free implantation. In this article, about a way to specify surface potential of negative-ion implanted insulator by secondary-electron-energy distribution, its principle and preliminary experimental results are described. By a measuring system with retarding field type energy analyzer, energy distribution of secondary electron from insulator of Fused Quartz in negative-carbon-ion implantation was measured. As a result the peak-shift of its energy distribution resulted according with the surface potential of insulator. It was found that surface potential of insulator is negatively charged by only several volts. Thus, negative-ion implanted insulator reduced its surface charge-up potential (without any electron supply). Therefore negative-ion implantation is considered to be much more effective method than conventional positive-ion implantation. (author)

Thickness-dependent blue shift in the excitonic peak of conformally grown ZnO:Al on ion-beam fabricated self-organized Si ripples

Energy Technology Data Exchange (ETDEWEB)

Basu, T.; Kumar, M.; Som, T., E-mail: tsom@iopb.res.in [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India); Nandy, S. [CENIMAT, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica 2829 516 (Portugal); Satpati, B. [Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, Kolkata 700 064 (India); Saini, C. P.; Kanjilal, A. [Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, Uttar Pradesh 201 314 (India)

2015-09-14

Al-doped ZnO (AZO) thin films of thicknesses 5,10, 15, 20, and 30 nm were deposited on 500 eV argon ion-beam fabricated nanoscale self-organized rippled-Si substrates at room temperature and are compared with similar films deposited on pristine-Si substrates (without ripples). It is observed that morphology of self-organized AZO films is driven by the underlying substrate morphology. For instance, for pristine-Si substrates, a granular morphology evolves for all AZO films. On the other hand, for rippled-Si substrates, morphologies having chain-like arrangement (anisotropic in nature) are observed up to a thickness of 20 nm, while a granular morphology evolves (isotropic in nature) for 30 nm-thick film. Photoluminescence studies reveal that excitonic peaks corresponding to 5–15 nm-thick AZO films, grown on rippled-Si templates, show a blue shift of 8 nm and 3 nm, respectively, whereas the peak shift is negligible for 20-nm thick film (with respect to their pristine counter parts). The observed blue shifts are substantiated by diffuse reflectance study and attributed to quantum confinement effect, associated with the size of the AZO grains and their spatial arrangements driven by the anisotropic morphology of underlying rippled-Si templates. The present findings will be useful for making tunable AZO-based light-emitting devices.

The replacement principle in networked economies with single-peaked preferences

DEFF Research Database (Denmark)

Szwagrzak, Karol

2016-01-01

disequilibrium prices, etc. In these contexts suppliers and demanders naturally have single-peaked preferences. We evaluate transfer rules on the basis of the “replacement principle” (Thomson, J Econ Theory 76(1):145–168 1997; Moulin, Q J Econ 102:769–783 1987), the requirement that a change in an agent......’s preferences affects all other agents in the same direction in terms of welfare. We find that the only Pareto-efficient, participation-compatible, replication-invariant, and envy-free rule satisfying an appropriate formulation of the replacement principle is the “egalitarian rule” introduced by Bochet et al....... (Theor Econ 7:395–423 2012)....

Detecting and accounting for multiple sources of positional variance in peak list registration analysis and spin system grouping.

Science.gov (United States)

Smelter, Andrey; Rouchka, Eric C; Moseley, Hunter N B

2017-08-01

Peak lists derived from nuclear magnetic resonance (NMR) spectra are commonly used as input data for a variety of computer assisted and automated analyses. These include automated protein resonance assignment and protein structure calculation software tools. Prior to these analyses, peak lists must be aligned to each other and sets of related peaks must be grouped based on common chemical shift dimensions. Even when programs can perform peak grouping, they require the user to provide uniform match tolerances or use default values. However, peak grouping is further complicated by multiple sources of variance in peak position limiting the effectiveness of grouping methods that utilize uniform match tolerances. In addition, no method currently exists for deriving peak positional variances from single peak lists for grouping peaks into spin systems, i.e. spin system grouping within a single peak list. Therefore, we developed a complementary pair of peak list registration analysis and spin system grouping algorithms designed to overcome these limitations. We have implemented these algorithms into an approach that can identify multiple dimension-specific positional variances that exist in a single peak list and group peaks from a single peak list into spin systems. The resulting software tools generate a variety of useful statistics on both a single peak list and pairwise peak list alignment, especially for quality assessment of peak list datasets. We used a range of low and high quality experimental solution NMR and solid-state NMR peak lists to assess performance of our registration analysis and grouping algorithms. Analyses show that an algorithm using a single iteration and uniform match tolerances approach is only able to recover from 50 to 80% of the spin systems due to the presence of multiple sources of variance. Our algorithm recovers additional spin systems by reevaluating match tolerances in multiple iterations. To facilitate evaluation of the

Orientation-dependent surface core-level shifts and chemical shifts on clean and H 2S-covered GaAs

Science.gov (United States)

Ranke, W.; Finster, J.; Kuhr, H. J.

1987-08-01

Photoelectron spectra of the As 3d and Ga 3d core levels were studied in situ on a cylindrically shaped GaAs single crystal for the six inequivalent orientations (001), (113), (111), (110), (11¯1) and (11¯3). On the clean surface, prepared by molecular beam epitaxy (MBE), surface core levels are shifted by 0.25 to 0.55 eV towards smaller binding energy (BE) for As 3d and -0.25 to -0.35 eV towards higher BE for Ga, depending on orientation. Additional As causes As 3d contributions shifted between -0.45 and -0.7 eV towards higher BE. The position and intensity of them is influenced by H 2S adsorption. At 150 K, H 2S adsorbs preferentially on As sites. As chemical shifts appear at -0.6 to -0.9 eV towards higher BE. Simultaneously, As accumulation occurs on all orientations with the exception of (110). High temperature adsorption (550 K, 720 K) influences mainly the Ga 3d peaks. Two peaks shifted by about -0.45 and -0.8 eV towards higher Be were found which are attributed to Ga atoms with one or two sulfur ligands, respectively. At 720 K, also As depletion is observed. The compatibility of surface core-level positions and intensities with recent structural models for the (111) and (11¯1) surfaces is discussed.

Peak stresses shift from femoral tunnel aperture to tibial tunnel aperture in lateral tibial tunnel ACL reconstructions: a 3D graft-bending angle measurement and finite-element analysis.

Science.gov (United States)

Van Der Bracht, Hans; Tampere, Thomas; Beekman, Pieter; Schepens, Alexander; Devriendt, Wouter; Verdonk, Peter; Victor, Jan

2018-02-01

To investigate the effect of tibial tunnel orientation on graft-bending angle and stress distribution in the ACL graft. Eight cadaveric knees were scanned in extension, 45°, 90°, and full flexion. 3D reconstructions with anatomically placed anterior cruciate ligament (ACL) grafts were constructed with Mimics 14.12 ® . 3D graft-bending angles were measured for classic medial tibial tunnels (MTT) and lateral tibial tunnels (LTT) with different drill-guide angles (DGA) (45°, 55°, 65°, and 75°). A pivot shift was performed on 1 knee in a finite-element analysis. The peak stresses in the graft were calculated for eight different tibial tunnel orientations. In a classic anatomical ACL repair, the largest graft-bending angle and peak stresses are seen at the femoral tunnel aperture. The use of a different DGA at the tibial side does not change the graft-bending angle at the femoral side or magnitude of peak stresses significantly. When using LTT, the largest graft-bending angles and peak stresses are seen at the tibial tunnel aperture. In a classic anatomical ACL repair, peak stresses in the ACL graft are found at the femoral tunnel aperture. When an LTT is used, peak stresses are similar compared to classic ACL repairs, but the location of the peak stress will shift from the femoral tunnel aperture towards the tibial tunnel aperture. the risk of graft rupture is similar for both MTTs and LTTs, but the location of graft rupture changes from the femoral tunnel aperture towards the tibial tunnel aperture, respectively. I.

A new approach way for white organic light-emitting diodes based on single emitting layer and large stokes shift.

Science.gov (United States)

Kim, Beomjin; Park, Youngil; Shin, Yunseop; Lee, Jiwon; Shin, Hwangyu; Park, Jongwook

2014-07-01

New red dopant, DPPZ based on porphyrin moiety was synthesized. DPPZ showed UV-Vis and PL maximum values of 412 and 638 nm, indicating the large stokes shift. New blue host compound, TATa was also synthesized and used for co-mixed white emission. TATa exhibited UV-Vis. and PL maximum values of 403 nm and 463 nm in film state. Thus, when two compounds are used as co-mixed emitter in OLED device, there is no energy transfer from blue emission of TATa to DPPZ due to large stokes shift of DPPZ. Based on the PL result, it is available to realize two-colored white in PL and EL spectra. As a result of this, two-mixed compounds showed vivid their own PL emission peaks of 466 and 638 nm in film state. Also, white OLED device using two-mixed compounds system was fabricated. EL spectrum shows 481 and 646 nm peaks and two separate EL peaks. As the operation voltage is increased from 8 to 11 V, EL spectrum does not change the peak shape and maximum wavelength values. EL performance of white device showed 0.041 cd/A, 0.018 Im/W, and CIE (0.457, 0.331) at 8 V.

Modelling and analysis of a novel compressed air energy storage system for trigeneration based on electrical energy peak load shifting

International Nuclear Information System (INIS)

Lv, Song; He, Wei; Zhang, Aifeng; Li, Guiqiang; Luo, Bingqing; Liu, Xianghua

2017-01-01

Highlights: • A new CAES system for trigeneration based on electrical peak load shifting is proposed. • The theoretical models and the thermodynamics process are established and analyzed. • The relevant parameters influencing its performance have been discussed and optimized. • A novel energy and economic evaluation methods is proposed to evaluate the performance of the system. - Abstract: The compressed air energy storage (CAES) has made great contribution to both electricity and renewable energy. In the pursuit of reduced energy consumption and relieving power utility pressure effectively, a novel trigeneration system based on CAES for cooling, heating and electricity generation by electrical energy peak load shifting is proposed in this paper. The cooling power is generated by the direct expansion of compressed air, and the heating power is recovered in the process of compression and storage. Based on the working principle of the typical CAES, the theoretical analysis of the thermodynamic system models are established and the characteristics of the system are analyzed. A novel method used to evaluate energy and economic performance is proposed. A case study is conducted, and the economic-social and technical feasibility of the proposed system are discussed. The results show that the trigeneration system works efficiently at relatively low pressure, and the efficiency is expected to reach about 76.3% when air is compressed and released by 15 bar. The annual monetary cost saving annually is about 53.9%. Moreover, general considerations about the proposed system are also presented.

Analytical results for a conditional phase shift between single-photon pulses in a nonlocal nonlinear medium

Science.gov (United States)

Viswanathan, Balakrishnan; Gea-Banacloche, Julio

2018-03-01

It has been suggested that second-order nonlinearities could be used for quantum logic at the single-photon level. Specifically, successive two-photon processes in principle could accomplish the phase shift (conditioned on the presence of two photons in the low-frequency modes) |011 〉→i |100 〉→-|011 〉 . We have analyzed a recent scheme proposed by Xia et al. [Phys. Rev. Lett. 116, 023601 (2016)], 10.1103/PhysRevLett.116.023601 to induce such a conditional phase shift between two single-photon pulses propagating at different speeds through a nonlinear medium with a nonlocal response. We present here an analytical solution for the most general case, i.e., for an arbitrary response function, initial state, and pulse velocity, which supports their numerical observation that a π phase shift with unit fidelity is possible, in principle, in an appropriate limit. We also discuss why this is possible in this system, despite the theoretical objections to the possibility of conditional phase shifts on single photons that were raised some time ago by Shapiro [Phys. Rev. A 73, 062305 (2006)], 10.1103/PhysRevA.73.062305 and by Gea-Banacloche [Phys. Rev. A 81, 043823 (2010)], 10.1103/PhysRevA.81.043823 one of us.

Effect of single interstitial impurity in iron-based superconductors with sign-changed s-wave pairing symmetry

Energy Technology Data Exchange (ETDEWEB)

Yu, Xiang-Long, E-mail: xlyu@theory.issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Liu, Da-Yong; Quan, Ya-Min; Zheng, Xiao-Jun [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Zou, Liang-Jian, E-mail: zou@theory.issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Department of Physics, University of Science and Technology of China, Hefei 230026 (China)

2015-12-15

Highlights: • Effects of single interstitial impurity are studied in iron-based superconductors. • Bound states within the superconducting gap can be induced. • The interstitial impurity can induce a π phase shift of pairing order parameter. • For strong magnetic scattering the bound-state peak can appear at the Fermi level. - Abstract: We employ the self-consistent Bogoliubov-de Gennes (BdG) formulation to investigate the effect of single interstitial nonmagnetic/magnetic impurity in iron-based superconductors with s ± -wave pairing symmetry. We find that both the nonmagnetic and magnetic impurities can induce bound states within the superconducting (SC) gap and a π phase shift of SC order parameter at the impurity site. However, different from the interstitial-nonmagnetic-impurity case characterized by two symmetric peaks with respect to zero energy, the interstitial magnetic one only induces single bound-state peak. In the strong scattering regime this peak can appear at the Fermi level, which has been observed in the recent scanning tunneling microscope (STM) experiment of Fe(Te,Se) superconductor with interstitial Fe impurities (Yin et al. 2015 [44]). This novel single in-gap peak feature also distinguishes the interstitial case from the substitutional one with two peaks. These results provide important information for comparing the different impurity effects in the iron-based superconductors.

Fast Metabolite Identification in Nuclear Magnetic Resonance Metabolomic Studies: Statistical Peak Sorting and Peak Overlap Detection for More Reliable Database Queries.

Science.gov (United States)

Hoijemberg, Pablo A; Pelczer, István

2018-01-05

A lot of time is spent by researchers in the identification of metabolites in NMR-based metabolomic studies. The usual metabolite identification starts employing public or commercial databases to match chemical shifts thought to belong to a given compound. Statistical total correlation spectroscopy (STOCSY), in use for more than a decade, speeds the process by finding statistical correlations among peaks, being able to create a better peak list as input for the database query. However, the (normally not automated) analysis becomes challenging due to the intrinsic issue of peak overlap, where correlations of more than one compound appear in the STOCSY trace. Here we present a fully automated methodology that analyzes all STOCSY traces at once (every peak is chosen as driver peak) and overcomes the peak overlap obstacle. Peak overlap detection by clustering analysis and sorting of traces (POD-CAST) first creates an overlap matrix from the STOCSY traces, then clusters the overlap traces based on their similarity and finally calculates a cumulative overlap index (COI) to account for both strong and intermediate correlations. This information is gathered in one plot to help the user identify the groups of peaks that would belong to a single molecule and perform a more reliable database query. The simultaneous examination of all traces reduces the time of analysis, compared to viewing STOCSY traces by pairs or small groups, and condenses the redundant information in the 2D STOCSY matrix into bands containing similar traces. The COI helps in the detection of overlapping peaks, which can be added to the peak list from another cross-correlated band. POD-CAST overcomes the generally overlooked and underestimated presence of overlapping peaks and it detects them to include them in the search of all compounds contributing to the peak overlap, enabling the user to accelerate the metabolite identification process with more successful database queries and searching all tentative

High peak-power kilohertz laser system employing single-stage multi-pass amplification

Science.gov (United States)

Shan, Bing; Wang, Chun; Chang, Zenghu

2006-05-23

The present invention describes a technique for achieving high peak power output in a laser employing single-stage, multi-pass amplification. High gain is achieved by employing a very small "seed" beam diameter in gain medium, and maintaining the small beam diameter for multiple high-gain pre-amplification passes through a pumped gain medium, then leading the beam out of the amplifier cavity, changing the beam diameter and sending it back to the amplifier cavity for additional, high-power amplification passes through the gain medium. In these power amplification passes, the beam diameter in gain medium is increased and carefully matched to the pump laser's beam diameter for high efficiency extraction of energy from the pumped gain medium. A method of "grooming" the beam by means of a far-field spatial filter in the process of changing the beam size within the single-stage amplifier is also described.

Time evolution, Lamb shift, and emission spectra of spontaneous emission of two identical atoms

International Nuclear Information System (INIS)

Wang Dawei; Li Zhenghong; Zheng Hang; Zhu Shiyao

2010-01-01

A unitary transformation method is used to investigate the dynamic evolution of two multilevel atoms, in the basis of symmetric and antisymmetric states, with one atom being initially prepared in the first excited state and the other in the ground state. The unitary transformation guarantees that our calculations are based on the ground state of the atom-field system and the self-energy is subtracted at the beginning. The total Lamb shifts of the symmetric and antisymmetric states are divided into transformed shift and dynamic shift. The transformed shift is due to emitting and reabsorbing of virtual photons, by a single atom (nondynamic single atomic shift) and between the two atoms (quasi-static shift). The dynamic shift is due to the emitting and reabsorbing of real photons, by a single atom (dynamic single atomic shift) and between the two atoms (dynamic interatomic shift). The emitting and reabsorbing of virtual and real photons between the two atoms result in the interatomic shift, which does not exist for the one-atom case. The spectra at the long-time limit are calculated. If the distance between the two atoms is shorter than or comparable to the wavelength, the strong coupling between the two atoms splits the spectrum into two peaks, one from the symmetric state and the other from the antisymmetric state. The origin of the red or blue shifts for the symmetric and antisymmetric states mainly lies in the negative or positive interaction energy between the two atoms. In the investigation of the short time evolution, we find the modification of the effective density of states by the interaction between two atoms can modulate the quantum Zeno and quantum anti-Zeno effects in the decays of the symmetric and antisymmetric states.

Dispersion-convolution model for simulating peaks in a flow injection system.

Science.gov (United States)

Pai, Su-Cheng; Lai, Yee-Hwong; Chiao, Ling-Yun; Yu, Tiing

2007-01-12

A dispersion-convolution model is proposed for simulating peak shapes in a single-line flow injection system. It is based on the assumption that an injected sample plug is expanded due to a "bulk" dispersion mechanism along the length coordinate, and that after traveling over a distance or a period of time, the sample zone will develop into a Gaussian-like distribution. This spatial pattern is further transformed to a temporal coordinate by a convolution process, and finally a temporal peak image is generated. The feasibility of the proposed model has been examined by experiments with various coil lengths, sample sizes and pumping rates. An empirical dispersion coefficient (D*) can be estimated by using the observed peak position, height and area (tp*, h* and At*) from a recorder. An empirical temporal shift (Phi*) can be further approximated by Phi*=D*/u2, which becomes an important parameter in the restoration of experimental peaks. Also, the dispersion coefficient can be expressed as a second-order polynomial function of the pumping rate Q, for which D*(Q)=delta0+delta1Q+delta2Q2. The optimal dispersion occurs at a pumping rate of Qopt=sqrt[delta0/delta2]. This explains the interesting "Nike-swoosh" relationship between the peak height and pumping rate. The excellent coherence of theoretical and experimental peak shapes confirms that the temporal distortion effect is the dominating reason to explain the peak asymmetry in flow injection analysis.

Ion implantation effects in single crystal Si investigated by Raman spectroscopy

International Nuclear Information System (INIS)

Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

2009-01-01

A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

Frequency domain phase retrieval of simultaneous multi-wavelength phase-shifting interferometry

International Nuclear Information System (INIS)

Yin, Zhenxing; Zhong, Liyun; Xu, Xiaofei; Zhang, Wangping; Lu, Xiaoxu; Tian, Jindong

2016-01-01

In simultaneous multi-wavelength phase-shifting interferometry, we propose a novel frequency domain phase retrieval (FDPR) algorithm. First, using only a one-time phase-shifting operation, a sequence of simultaneous multi-wavelength phase-shifting interferograms (SPSMWIs) are captured by a monochrome charge-coupled device. Second, by performing a Fourier transform for each pixel of SPSMWIs, the wrapped phases of each wavelength can be retrieved from the complex amplitude located in the spectral peak of each wavelength. Finally, the phase of the synthetic wavelength can be obtained by the subtraction between the wrapped phases of a single wavelength. In this study, the principle and the application condition of the proposed approach are discussed. Both the simulation and the experimental result demonstrate the simple and convenient performance of the proposed FDPR approach. (paper)

Analysis for reflection peaks of multiple-phase-shift based sampled fiber Bragg gratings and application in high channel-count filter design.

Science.gov (United States)

Wen, Kun Hua; Yan, Lian Shan; Pan, Wei; Luo, Bin; Zou, Xi Hua; Ye, Jia; Ma, Ya Nan

2009-10-10

An analytical expression for calculating the reflection-peak wavelengths (RPWs) of a uniform sampled fiber Bragg grating (SFBG) with the multiple-phase-shift (MPS) technique is derived through Fourier transform of the index modulation. The new expression can accurately depict the RPWs incorporating various parameters such as the duty cycle and the DC index change. The effectiveness of the derived expression is further confirmed by comparing the RPWs estimated from the expression with the simulated reflective spectra using the piecewise uniform method. And the reflective spectrum has been well optimized by introducing the Gaussian apodization function to suppress the sidelobes without any wavelength shift on the RPWs. Then, a high-channel-count comb filter based on MPS is proposed by cascading two or more SFBGs with different Bragg periods but with the same RPWs. Noticeably, the RPWs of the new structured SFBG can also be accurately calculated through the expression. Furthermore, the number of spectral channels can be controlled by choosing gratings with specified difference Bragg periods.

Chemical shift-dependent apparent scalar couplings: An alternative concept of chemical shift monitoring in multi-dimensional NMR experiments

International Nuclear Information System (INIS)

Kwiatkowski, Witek; Riek, Roland

2003-01-01

The paper presents an alternative technique for chemical shift monitoring in a multi-dimensional NMR experiment. The monitored chemical shift is coded in the line-shape of a cross-peak through an apparent residual scalar coupling active during an established evolution period or acquisition. The size of the apparent scalar coupling is manipulated with an off-resonance radio-frequency pulse in order to correlate the size of the coupling with the position of the additional chemical shift. The strength of this concept is that chemical shift information is added without an additional evolution period and accompanying polarization transfer periods. This concept was incorporated into the three-dimensional triple-resonance experiment HNCA, adding the information of 1 H α chemical shifts. The experiment is called HNCA coded HA, since the chemical shift of 1 H α is coded in the line-shape of the cross-peak along the 13 C α dimension

Lateral shifting in one dimensional chiral photonic crystal

Energy Technology Data Exchange (ETDEWEB)

You Yuan, E-mail: yctcyouyuan@163.com [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China); Chen Changyuan [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China)

2012-07-01

We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

Lateral shifting in one dimensional chiral photonic crystal

International Nuclear Information System (INIS)

You Yuan; Chen Changyuan

2012-01-01

We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

PolyaPeak: Detecting Transcription Factor Binding Sites from ChIP-seq Using Peak Shape Information

Science.gov (United States)

Wu, Hao; Ji, Hongkai

2014-01-01

ChIP-seq is a powerful technology for detecting genomic regions where a protein of interest interacts with DNA. ChIP-seq data for mapping transcription factor binding sites (TFBSs) have a characteristic pattern: around each binding site, sequence reads aligned to the forward and reverse strands of the reference genome form two separate peaks shifted away from each other, and the true binding site is located in between these two peaks. While it has been shown previously that the accuracy and resolution of binding site detection can be improved by modeling the pattern, efficient methods are unavailable to fully utilize that information in TFBS detection procedure. We present PolyaPeak, a new method to improve TFBS detection by incorporating the peak shape information. PolyaPeak describes peak shapes using a flexible Pólya model. The shapes are automatically learnt from the data using Minorization-Maximization (MM) algorithm, then integrated with the read count information via a hierarchical model to distinguish true binding sites from background noises. Extensive real data analyses show that PolyaPeak is capable of robustly improving TFBS detection compared with existing methods. An R package is freely available. PMID:24608116

Condensing Raman spectrum for single-cell phenotype analysis

KAUST Repository

Sun, Shiwei; Wang, Xuetao; Gao, Xin; Ren, Lihui; Su, Xiaoquan; Bu, Dongbo; Ning, Kang

2015-01-01

In this work, we have proposed an approach called rDisc to discretize the original Raman spectrum into only a few (usually less than 20) representative peaks (Raman shifts). The approach has advantages in removing noises, and condensing the original spectrum. In particular, effective signal processing procedures were designed to eliminate noise, utilising wavelet transform denoising, baseline correction, and signal normalization. In the discretizing process, representative peaks were selected to signicantly decrease the Raman data size. More importantly, the selected peaks are chosen as suitable to serve as key biological markers to differentiate species and other cellular features. Additionally, the classication performance of discretized spectra was found to be comparable to full spectrum having more than 1000 Raman shifts. Overall, the discretized spectrum needs about 5storage space of a full spectrum and the processing speed is considerably faster. This makes rDisc clearly superior to other methods for single-cell classication.

Detecting carbon uptake and cellular allocation by individual algae in multispecies assemblages: Tracking carbon into single algal cells

Energy Technology Data Exchange (ETDEWEB)

Murdock, Justin N. [USDA Agricultural Research Service, National Sedimentation Laboratory, Oxford Mississippi; Department of Biology, Tennessee Technological University, Cookeville Tennessee

2015-11-03

Algal species vary in carbon (C) need and uptake rates. Understanding differences in C uptake and cellular allocation among species from natural communities will bring new insight into many ecosystem process questions including how species changes will alter energy availability and C sequestration in aquatic ecosystems. A major limitation of current methods that measure algal C incorporation is the inability to separate the response of individual species from mixed-species assemblages. I used Fourier-transform infrared microspectroscopy to qualitatively measure inorganic ¹³C isotope incorporation into individual algal cells in single species, two species, and natural phytoplankton assemblages. Lateral shifts in spectral peaks from ¹³C treatments were observed in all species. Comparison of peaks associated with carbohydrates, proteins, and lipids allowed for the detection of which individuals took in C, and which macromolecules the C was used to make. For example, shifts in Spirogyra spectral peaks showed substantial C incorporation in carbohydrates. Further, shifts in peaks at 1160 cm^-1, 1108 cm^-1, 1080 cm^-1, 1048 cm^-1, and 1030 cm^-1 suggested C was being allocated into cellulose. The natural phytoplankton assemblage demonstrated how C could be tracked into co-occurring species. A diatom had large shifts in protein and carbohydrate peaks, while a green alga and euglenoid had only a few shifts in protein related peaks. Fourier-transform infrared microspectroscopy is an established, label free method for measuring the chemical composition of algal cells. However, adding a label such as ¹³C isotope can greatly expand the technique's capabilities by qualitatively tracking C movement between inorganic and organic states within single cells.

Magnetoexcitons and Faraday rotation in single-walled carbon nanotubes and graphene nanoribbons

Science.gov (United States)

Have, Jonas; Pedersen, Thomas G.

2018-03-01

The magneto-optical response of single-walled carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) is studied theoretically, including excitonic effects. Both diagonal and nondiagonal response functions are obtained and employed to compute Faraday rotation spectra. For single-walled CNTs in a parallel field, the results show field-dependent splitting of the exciton absorption peaks caused by brightening a dark exciton state. Similarly, for GNRs in a perpendicular magnetic field, we observe a field-dependent shift of the exciton peaks and the emergence of an absorption peak above the energy gap. Results show that excitonic effects play a significant role in the optical response of both materials, particularly for the off-diagonal tensor elements.

Crystal identification for a dual-layer-offset LYSO based PET system via Lu-176 background radiation and mean shift algorithm

Science.gov (United States)

Wei, Qingyang; Ma, Tianyu; Xu, Tianpeng; Zeng, Ming; Gu, Yu; Dai, Tiantian; Liu, Yaqiang

2018-01-01

Modern positron emission tomography (PET) detectors are made from pixelated scintillation crystal arrays and readout by Anger logic. The interaction position of the gamma-ray should be assigned to a crystal using a crystal position map or look-up table. Crystal identification is a critical procedure for pixelated PET systems. In this paper, we propose a novel crystal identification method for a dual-layer-offset LYSO based animal PET system via Lu-176 background radiation and mean shift algorithm. Single photon event data of the Lu-176 background radiation are acquired in list-mode for 3 h to generate a single photon flood map (SPFM). Coincidence events are obtained from the same data using time information to generate a coincidence flood map (CFM). The CFM is used to identify the peaks of the inner layer using the mean shift algorithm. The response of the inner layer is deducted from the SPFM by subtracting CFM. Then, the peaks of the outer layer are also identified using the mean shift algorithm. The automatically identified peaks are manually inspected by a graphical user interface program. Finally, a crystal position map is generated using a distance criterion based on these peaks. The proposed method is verified on the animal PET system with 48 detector blocks on a laptop with an Intel i7-5500U processor. The total runtime for whole system peak identification is 67.9 s. Results show that the automatic crystal identification has 99.98% and 99.09% accuracy for the peaks of the inner and outer layers of the whole system respectively. In conclusion, the proposed method is suitable for the dual-layer-offset lutetium based PET system to perform crystal identification instead of external radiation sources.

On the energy shift the ECC cusp. Does the shift really exist?

International Nuclear Information System (INIS)

Sarkadi, L.; Barrachina, R.O.

2004-01-01

The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions are generally thought to be a divergence. Recently Shah et al., however, claimed that 'the ECC cusp is indeed a cusp, and not a divergence smoothed by the experiment'. These authors measured the ECC cusp for collisions of 10- and 20-keV protons with H 2 and He, and found that the peak was shifted to lower velocity than its expected position. We also carried out CTMC calculations (for the case of 20-keV protons on He) by which we demonstrated that the shift really exists but its value depends on the angular window of the electron detection. (K.A.)

Dynamic vortex-phase diagram of MgB2 single crystals near the peak-effect region

International Nuclear Information System (INIS)

Kim, Heon-Jung; Lee, Hyun-Sook; Kang, Byeongwon; Chowdhury, P.; Kim, Kyung-Hee; Park, Min-Seok; Lee, Sung-Ik

2006-01-01

The dynamic vortex-phase diagram of MgB 2 single crystals has been constructed by using voltage noise characteristics. Between the onset (H on ) and the peak (H p ) magnetic fields, crossovers from a state with large noises to a noise-free state were observed with increasing current while above H p , a reverse behavior was found. We will discuss the dynamic vortex phase diagram and the possible origins of the crossovers

Real-time bilinear rotation decoupling in absorptive mode J-spectroscopy: Detecting low-intensity metabolite peak close to high-intensity metabolite peak with convenience

Science.gov (United States)

Verma, Ajay; Baishya, Bikash

2016-05-01

;Pure shift; NMR spectra display singlet peak per chemical site. Thus, high resolution is offered at the cost of valuable J-coupling information. In the present work, real-time BIRD (BIlinear Rotation Decoupling) is applied to the absorptive-mode 2D J-spectroscopy to provide pure shift spectrum in the direct dimension and J-coupling information in the indirect dimension. Quite often in metabolomics, proton NMR spectra from complex bio-fluids display tremendous signal overlap. Although conventional J-spectroscopy in principle overcomes this problem by separating the multiplet information from chemical shift information, however, only magnitude mode of the experiment is practical, sacrificing much of the potential high resolution that could be achieved. Few J-spectroscopy methods have been reported so far that produce high-resolution pure shift spectrum along with J-coupling information for crowded spectral regions. In the present work, high-quality J-resolved spectrum from important metabolomic mixture such as tissue extract from rat cortex is demonstrated. Many low-intensity metabolite peaks which are obscured by the broad dispersive tails from high-intensity metabolite peaks in regular magnitude mode J-spectrum can be clearly identified in real-time BIRD J-resolved spectrum. The general practice of removing such spectral overlap is tedious and time-consuming as it involves repeated sample preparation to change the pH of the tissue extract sample and subsequent spectra recording.

Note on beam--beam tune shift in single ring multi bunch mode

International Nuclear Information System (INIS)

Month, M.

1978-01-01

If many identical counter-rotating bunches of protons and antiprotons are stored in a single ring, they will have identical orbits. The question is: Is this total tune shift relevant to the problem of beam stability. The answer is: not in general. The nonlinear force is described by its ''strength'', Δν/sub I/, for each bunch interaction individually. It is not at all clear that the sum of the individual Δν/sub I/ is the significant quantity

Effects of SiO2 encapsulation and laser processing on single CdTe/ZnTe quantum dots grown on Si (001) substrates

International Nuclear Information System (INIS)

Lee, Hong Seok; Rastelli, Armando; Schmidt, Oliver G.; Kim, Tae Whan; Lee, In Won

2011-01-01

Micro-photoluminescence (μ-PL) measurements are carried out to investigate the effects of SiO 2 encapsulation and laser processing of single CdTe/ZnTe quantum dots (QDs) grown on Si (001) substrates by using molecular beam epitaxy and atomic layer epitaxy. After laser processing, the μ-PL peak shift for the 200-nm SiO 2 capped single QD is larger than that of the as-grown sample. The large μ-PL peak shift in the 200-nm SiO 2 capped sample is related to the compressive stress induced by the ZnTe cap layer during laser processing. These results indicate that SiO 2 encapsulation and laser processing represent effective methods for achieving local wavelength tuning in single QDs.

Development of a personal obligation to shift electricity use: Initial determinants and maintenance over time

Energy Technology Data Exchange (ETDEWEB)

Linz, D.; Heberlein, T.

1984-03-01

The present study is an attempt to determine if the beliefs which underly the formation of an obligation to shift electricity use among household consumers also contribute to maintenance of the obligation over time. Utility customer beliefs about and obligation toward shifting electricity use in their households from on-peak to off-peak times were examined in 1977, when the customers had no behavioral experience with electricity shifting. In 1979, after two years of experience with shifting appliance use from on-peak to off-peak times, customers were again surveyed and the same variables measured. The results indicated that the formation of a feeling of obligation to shift electricity in 1977 use was marginally dependent on other beliefs. By 1979, these variables were completely supplanted by the subjects' self-perception of their shifting behavior. While cognitive variables are important in the initial formation of a personal obligation to engage in shifting electricity use, the perpetuation of a feeling of obligation to shift over a period of years depends on perception of how often electricity shifting was undertaken and how much electricity had been shifted from on- to off-peak times.

Stokes shift spectroscopy for breast cancer diagnosis

Science.gov (United States)

Jeyasingh, Ebenezar; Prakashrao, Aruna; Singaravelu, Ganesan

2010-02-01

The objective of this study is to assess the diagnostic potential of stokes shift (SS) spectroscopy (SSS) for normal and different pathological breast tissues such as fibroadenoma and infiltrating ductal carcinoma. The SS spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological breast tissues were observed. The SS spectra of normal and different pathological breast tissues shows the distinct peaks around 300, 350, 450, 500 and 600 nm may be attributed to tryptophan, collagen, NADH, flavin and porphyrin respectively. Using SSS technique one can obtain all the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological breast tissues are verified by different ratio parameters.

Sorting photons of different rotational Doppler shifts (RDS) by orbital angular momentum of single-photon with spin-orbit-RDS entanglement.

Science.gov (United States)

Chen, Lixiang; She, Weilong

2008-09-15

We demonstrate that single photons from a rotating q-plate exhibit an entanglement in three degrees of freedom of spin, orbital angular momentum, and the rotational Doppler shift (RDS) due to the nonconservation of total spin and orbital angular momenta. We find that the rotational Doppler shift deltaomega = Omega((delta)s + deltal) , where s, l and Omega are quantum numbers of spin, orbital angular momentum, and rotating velocity of the q-plate, respectively. Of interest is that the rotational Doppler shift directly reflects the rotational symmetry of q-plates and can be also expressed as deltaomega = (Omega)n , where n = 2(q-1) denotes the fold number of rotational symmetry. Besides, based on this single-photon spin-orbit-RDS entanglement, we propose an experimental scheme to sort photons of different frequency shifts according to individual orbital angular momentum.

Condensing Raman spectrum for single-cell phenotype analysis

KAUST Repository

Sun, Shiwei

2015-12-09

Background In recent years, high throughput and non-invasive Raman spectrometry technique has matured as an effective approach to identification of individual cells by species, even in complex, mixed populations. Raman profiling is an appealing optical microscopic method to achieve this. To fully utilize Raman proling for single-cell analysis, an extensive understanding of Raman spectra is necessary to answer questions such as which filtering methodologies are effective for pre-processing of Raman spectra, what strains can be distinguished by Raman spectra, and what features serve best as Raman-based biomarkers for single-cells, etc. Results In this work, we have proposed an approach called rDisc to discretize the original Raman spectrum into only a few (usually less than 20) representative peaks (Raman shifts). The approach has advantages in removing noises, and condensing the original spectrum. In particular, effective signal processing procedures were designed to eliminate noise, utilising wavelet transform denoising, baseline correction, and signal normalization. In the discretizing process, representative peaks were selected to signicantly decrease the Raman data size. More importantly, the selected peaks are chosen as suitable to serve as key biological markers to differentiate species and other cellular features. Additionally, the classication performance of discretized spectra was found to be comparable to full spectrum having more than 1000 Raman shifts. Overall, the discretized spectrum needs about 5storage space of a full spectrum and the processing speed is considerably faster. This makes rDisc clearly superior to other methods for single-cell classication.

Phenological shifts conserve thermal niches in North American birds and reshape expectations for climate-driven range shifts.

Science.gov (United States)

Socolar, Jacob B; Epanchin, Peter N; Beissinger, Steven R; Tingley, Morgan W

2017-12-05

Species respond to climate change in two dominant ways: range shifts in latitude or elevation and phenological shifts of life-history events. Range shifts are widely viewed as the principal mechanism for thermal niche tracking, and phenological shifts in birds and other consumers are widely understood as the principal mechanism for tracking temporal peaks in biotic resources. However, phenological and range shifts each present simultaneous opportunities for temperature and resource tracking, although the possible role for phenological shifts in thermal niche tracking has been widely overlooked. Using a canonical dataset of Californian bird surveys and a detectability-based approach for quantifying phenological signal, we show that Californian bird communities advanced their breeding phenology by 5-12 d over the last century. This phenological shift might track shifting resource peaks, but it also reduces average temperatures during nesting by over 1 °C, approximately the same magnitude that average temperatures have warmed over the same period. We further show that early-summer temperature anomalies are correlated with nest success in a continental-scale database of bird nests, suggesting avian thermal niches might be broadly limited by temperatures during nesting. These findings outline an adaptation surface where geographic range and breeding phenology respond jointly to constraints imposed by temperature and resource phenology. By stabilizing temperatures during nesting, phenological shifts might mitigate the need for range shifts. Global change ecology will benefit from further exploring phenological adjustment as a potential mechanism for thermal niche tracking and vice versa.

Difference in peak weight transfer and timing based on golf handicap.

Science.gov (United States)

Queen, Robin M; Butler, Robert J; Dai, Boyi; Barnes, C Lowry

2013-09-01

Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

Single-photon superradiance and cooperative Lamb shift in an optoelectronic device (Conference Presentation)

Science.gov (United States)

Sirtori, Carlo

2017-02-01

Superradiance is one of the many fascinating phenomena predicted by quantum electrodynamics that have first been experimentally demonstrated in atomic systems and more recently in condensed matter systems like quantum dots, superconducting q-bits, cyclotron transitions and plasma oscillations in quantum wells (QWs). It occurs when a dense collection of N identical two-level emitters are phased via the exchange of photons, giving rise to enhanced light-matter interaction, hence to a faster emission rate. Of great interest is the regime where the ensemble interacts with one photon only and therefore all of the atoms, but one, are in the ground state. In this case the quantum superposition of all possible configurations produces a symmetric state that decays radiatively with a rate N times larger than that of the individual oscillators. This phenomenon, called single photon superradiance, results from the exchange of real photons among the N emitters. Yet, to single photon superradiance is also associated another collective effect that renormalizes the emission frequency, known as cooperative Lamb shift. In this work, we show that single photon superradiance and cooperative Lamb shift can be engineered in a semiconductor device by coupling spatially separated plasma resonances arising from the collective motion of confined electrons in QWs. These resonances hold a giant dipole along the growth direction z and have no mutual Coulomb coupling. They thus behave as a collection of macro-atoms on different positions along the z axis. Our device is therefore a test bench to simulate the low excitation regime of quantum electrodynamics.

Stark-shift induced resonances in multiphoton ionization

International Nuclear Information System (INIS)

Potvliege, R M; Vuci, Svetlana

2006-01-01

The resonance enhancements marking the ATI spectrum of argon are discussed in the light of a recently compiled map of the quasienergies of this atom. Many of the dressed excited states of interest shift nonponderomotively in complicated ways, but keep an ionization width narrow enough to produce sharp substructures of both low and high ATI peaks through Stark-shift induced resonances. The most prominent enhancement observed in the high-order ATI peaks originates from ionization from the dressed ground state perturbed by the influence of neighbouring resonant dressed states

Shifting Control Algorithm for a Single-Axle Parallel Plug-In Hybrid Electric Bus Equipped with EMT

Directory of Open Access Journals (Sweden)

Yunyun Yang

2014-01-01

Full Text Available Combining the characteristics of motor with fast response speed, an electric-drive automated mechanical transmission (EMT is proposed as a novel type of transmission in this paper. Replacing the friction synchronization shifting of automated manual transmission (AMT in HEVs, the EMT can achieve active synchronization of speed shifting. The dynamic model of a single-axle parallel PHEV equipped with the EMT is built up, and the dynamic properties of the gearshift process are also described. In addition, the control algorithm is developed to improve the shifting quality of the PHEV equipped with the EMT in all its evaluation indexes. The key techniques of changing the driving force gradient in preshifting and shifting compensation phases as well as of predicting the meshing speed in the gear meshing phase are also proposed. Results of simulation, bench test, and real road test demonstrate that the proposed control algorithm can reduce the gearshift jerk and the power interruption time noticeably.

Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy

International Nuclear Information System (INIS)

Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy

2015-01-01

Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), 1 H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong 1 H– 1 H homonuclear dipolar couplings and narrow 1 H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) 1 H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about 1 H– 1 H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical

Hydration-coupled protein boson peak measured by incoherent neutron scattering

International Nuclear Information System (INIS)

Nakagawa, Hiroshi; Kataoka, Mikio; Joti, Yasumasa; Kitao, Akio; Shibata, Kaoru; Tokuhisa, Atsushi; Tsukushi, Itaru; Go, Nobuhiro

2006-01-01

The boson peak of a protein was examined in relation to hydration using staphylococcal nuclease. Although the boson peak is commonly observed in synthetic polymers, glassy materials and amorphous materials, the origin of the boson peak is not fully understood. The motions that contribute to the peak are harmonic vibrations. Upon hydration the peak frequency shifts to a higher frequency and the effective force constant of the vibration increases at low temperatures, suggesting that the protein energy surface is modified. Hydration of the protein leads to a more rugged surface and the vibrational motions are trapped within the local minimum at cryogenic temperatures. The origin of the protein boson peak may be related to this rugged energy surface

Peak picking multidimensional NMR spectra with the contour geometry based algorithm CYPICK

International Nuclear Information System (INIS)

Würz, Julia M.; Güntert, Peter

2017-01-01

The automated identification of signals in multidimensional NMR spectra is a challenging task, complicated by signal overlap, noise, and spectral artifacts, for which no universally accepted method is available. Here, we present a new peak picking algorithm, CYPICK, that follows, as far as possible, the manual approach taken by a spectroscopist who analyzes peak patterns in contour plots of the spectrum, but is fully automated. Human visual inspection is replaced by the evaluation of geometric criteria applied to contour lines, such as local extremality, approximate circularity (after appropriate scaling of the spectrum axes), and convexity. The performance of CYPICK was evaluated for a variety of spectra from different proteins by systematic comparison with peak lists obtained by other, manual or automated, peak picking methods, as well as by analyzing the results of automated chemical shift assignment and structure calculation based on input peak lists from CYPICK. The results show that CYPICK yielded peak lists that compare in most cases favorably to those obtained by other automated peak pickers with respect to the criteria of finding a maximal number of real signals, a minimal number of artifact peaks, and maximal correctness of the chemical shift assignments and the three-dimensional structure obtained by fully automated assignment and structure calculation.

Peak picking multidimensional NMR spectra with the contour geometry based algorithm CYPICK

Energy Technology Data Exchange (ETDEWEB)

Würz, Julia M.; Güntert, Peter, E-mail: guentert@em.uni-frankfurt.de [Goethe University Frankfurt am Main, Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (Germany)

2017-01-15

The automated identification of signals in multidimensional NMR spectra is a challenging task, complicated by signal overlap, noise, and spectral artifacts, for which no universally accepted method is available. Here, we present a new peak picking algorithm, CYPICK, that follows, as far as possible, the manual approach taken by a spectroscopist who analyzes peak patterns in contour plots of the spectrum, but is fully automated. Human visual inspection is replaced by the evaluation of geometric criteria applied to contour lines, such as local extremality, approximate circularity (after appropriate scaling of the spectrum axes), and convexity. The performance of CYPICK was evaluated for a variety of spectra from different proteins by systematic comparison with peak lists obtained by other, manual or automated, peak picking methods, as well as by analyzing the results of automated chemical shift assignment and structure calculation based on input peak lists from CYPICK. The results show that CYPICK yielded peak lists that compare in most cases favorably to those obtained by other automated peak pickers with respect to the criteria of finding a maximal number of real signals, a minimal number of artifact peaks, and maximal correctness of the chemical shift assignments and the three-dimensional structure obtained by fully automated assignment and structure calculation.

The dislocation-internal friction peak γ in tantalum

International Nuclear Information System (INIS)

Baur, J.; Benoit, W.; Schultz, H.

1989-01-01

Torsion-pendulum measurements were carried out on high-purity single crystal specimens of tantalum, having extremely low oxygen contents ( 2 peak, which appears close to γ is small traces of oxygen are presents. The γ 2 peak was formerly explained as a ''dislocation-enhanced Snoek peak''. The γ peak recovers at the peak temperature, whereas the γ 2 peak is more stable. On the basis of their results, and making use of earlier investigations of Rodrian and Schultz, the authors suggest that γ 2 is modified γ relaxation, related to screw-dislocation segments, stabilized by oxygen-decorated kinks. The stability of the γ 2 peak allows an accurate determination of the activation energy, found to be 1.00 +- 0.03 eV. This value is distinctly lower than the activation energy of the oxygen Snoek effect (1.10 eV) and is related here to the mechanism of ''kink-pair formation'' in screw dislocations, as the original γ peak. The numerical value is compatible with recent values derived from flow-stress measurements. The peak γ 2 shows increasing stability with increasing oxygen content. This is explained by single- and multi-decorated kinks

Automatic fitting of Gaussian peaks using abductive machine learning

Science.gov (United States)

Abdel-Aal, R. E.

1998-02-01

Analytical techniques have been used for many years for fitting Gaussian peaks in nuclear spectroscopy. However, the complexity of the approach warrants looking for machine-learning alternatives where intensive computations are required only once (during training), while actual analysis on individual spectra is greatly simplified and quickened. This should allow the use of simple portable systems for fast and automated analysis of large numbers of spectra, particularly in situations where accuracy may be traded for speed and simplicity. This paper proposes the use of abductive networks machine learning for this purpose. The Abductory Induction Mechanism (AIM) tool was used to build models for analyzing both single and double Gaussian peaks in the presence of noise depicting statistical uncertainties in collected spectra. AIM networks were synthesized by training on 1000 representative simulated spectra and evaluated on 500 new spectra. A classifier network determines the multiplicity of single/double peaks with an accuracy of 5.8%. With statistical uncertainties corresponding to a peak count of 100, average percentage absolute errors for the height, position, and width of single peaks are 4.9, 2.9, and 4.2%, respectively. For double peaks, these average errors are within 7.0, 3.1, and 5.9%, respectively. Models have been developed which account for the effect of a linear background on a single peak. Performance is compared with a neural network application and with an analytical curve-fitting routine, and the new technique is applied to actual data of an alpha spectrum.

Automatic fitting of Gaussian peaks using abductive machine learning

International Nuclear Information System (INIS)

Abdel-Aal, R.E.

1998-01-01

Analytical techniques have been used for many years for fitting Gaussian peaks in nuclear spectroscopy. However, the complexity of the approach warrants looking for machine-learning alternatives where intensive computations are required only once (during training), while actual analysis on individual spectra is greatly simplified and quickened. This should allow the use of simple portable systems for fast and automated analysis of large numbers of spectra, particularly in situations where accuracy may be traded for speed and simplicity. This paper proposes the use of abductive networks machine learning for this purpose. The Abductory Induction Mechanism (AIM) tool was used to build models for analyzing both single and double Gaussian peaks in the presence of noise depicting statistical uncertainties in collected spectra. AIM networks were synthesized by training on 1,000 representative simulated spectra and evaluated on 500 new spectra. A classifier network determines the multiplicity of single/double peaks with an accuracy of 98%. With statistical uncertainties corresponding to a peak count of 100, average percentage absolute errors for the height, position, and width of single peaks are 4.9, 2.9, and 4.2%, respectively. For double peaks, these average errors are within 7.0, 3.1, and 5.9%, respectively. Models have been developed which account for the effect of a linear background on a single peak. Performance is compared with a neural network application and with an analytical curve-fitting routine, and the new technique is applied to actual data of an alpha spectrum

From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high γ-energies

International Nuclear Information System (INIS)

Kshetri, R

2012-01-01

In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for γ-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate method of calculating the peak-to-total ratio of other composite detectors, is shown. Experimental validation of our approach (for energies up to 8 MeV) has been confirmed considering the data of the SPI spectrometer. We have discussed about comparisons between various modes of operation and suppression cases. The present paper is the fifth in the series of papers on composite germanium detectors and for the first time discusses about the change in fold distribution and peak-to-total ratio for sophisticated detectors consisting of several modules of miniball, cluster and SPI detectors. Our work could provide a guidance in designing new composite detectors and in performing experimental studies with the existing detectors for high energy gamma-rays.

From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high γ-energies

Science.gov (United States)

Kshetri, R.

2012-12-01

In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for γ-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate method of calculating the peak-to-total ratio of other composite detectors, is shown. Experimental validation of our approach (for energies up to 8 MeV) has been confirmed considering the data of the SPI spectrometer. We have discussed about comparisons between various modes of operation and suppression cases. The present paper is the fifth in the series of papers on composite germanium detectors and for the first time discusses about the change in fold distribution and peak-to-total ratio for sophisticated detectors consisting of several modules of miniball, cluster and SPI detectors. Our work could provide a guidance in designing new composite detectors and in performing experimental studies with the existing detectors for high energy gamma-rays.

Frequency shift and hysteresis suppression in contact-mode AFM using contact stiffness modulation

Directory of Open Access Journals (Sweden)

Belhaq M.

2012-07-01

Full Text Available In this paper the frequency response shift and hysteresis suppression of contact-mode atomic force microscopy is investigated using parametric modulation of the contact stiffness. Based on the Hertzian contact theory, a lumped single degree of freedom oscillator is considered for modeling the cantilever dynamics contact-mode atomic force microscopy. We use the technique of direct partition of motion and the method of multiple scales to obtain, respectively, the slow dynamic and the corresponding slow flow of the system. As results, this study shows that the amplitude of the contact stiffness modulation has a significant effect on the frequency response. Specifically, increasing the amplitude of the stiffness modulation suppresses hysteresis, decreases the peak amplitude and produces shifts towards higher and lower frequencies.

Detecting Fermi-level shifts by Auger electron spectroscopy in Si and GaAs

Science.gov (United States)

Debehets, J.; Homm, P.; Menghini, M.; Chambers, S. A.; Marchiori, C.; Heyns, M.; Locquet, J. P.; Seo, J. W.

2018-05-01

In this paper, changes in surface Fermi-level of Si and GaAs, caused by doping and cleaning, are investigated by Auger electron spectroscopy. Based on the Auger voltage contrast, we compared the Auger transition peak energy but with higher accuracy by using a more accurate analyzer and an improved peak position determination method. For silicon, a peak shift as large as 0.46 eV was detected when comparing a cleaned p-type and n-type wafer, which corresponds rather well with the theoretical difference in Fermi-levels. If no cleaning was applied, the peak position did not differ significantly for both wafer types, indicating Fermi-level pinning in the band gap. For GaAs, peak shifts were detected after cleaning with HF and (NH4)2S-solutions in an inert atmosphere (N2-gas). Although the (NH4)2S-cleaning in N2 is very efficient in removing the oxygen from the surface, the observed Ga- and As-peak shifts are smaller than those obtained after the HF-cleaning. It is shown that the magnitude of the shift is related to the surface composition. After Si-deposition on the (NH4)2S-cleaned surface, the Fermi-level shifts back to a similar position as observed for an as-received wafer, indicating that this combination is not successful in unpinning the Fermi-level of GaAs.

Pulsed high-peak-power and single-frequency fibre laser design for LIDAR aircraft safety application

Science.gov (United States)

Liégeois, Flavien; Vercambre, Clément; Hernandez, Yves; Salhi, Mohamed; Giannone, Domenico

2006-09-01

Laser wind velocimeters work by monitoring the Doppler shift induced on the backscattered light by aerosols that are present in the air. Recently there has been a growing interest in the scientific community for developing systems operating at wavelengths near 1.5 μm and based on all-fibre lasers configuration. In this paper, we propose a new all-fibre laser source that is suitable for Doppler velocimetry in aircraft safety applications. The all-fibre laser has been specifically conceived for aircraft safety application. Our prototype has a conveniently narrow linewidth (9 kHz) and is modulated and amplified through an all fibre Master Oscillator Power Amplifier (MOPA) configuration. According to the measurements, we performed the final characteristics of the laser consist in a maximum peak power of 2.7 kW and an energy of 27 μJ energy per pulses of 10 ns at 30 kHz repetition rate. The only limiting factor of these performances is the Stimulated Brillouin Scattering.

Charge transfer at junctions of a single layer of graphene and a metallic single walled carbon nanotube.

Science.gov (United States)

Paulus, Geraldine L C; Wang, Qing Hua; Ulissi, Zachary W; McNicholas, Thomas P; Vijayaraghavan, Aravind; Shih, Chih-Jen; Jin, Zhong; Strano, Michael S

2013-06-10

Junctions between a single walled carbon nanotube (SWNT) and a monolayer of graphene are fabricated and studied for the first time. A single layer graphene (SLG) sheet grown by chemical vapor deposition (CVD) is transferred onto a SiO₂/Si wafer with aligned CVD-grown SWNTs. Raman spectroscopy is used to identify metallic-SWNT/SLG junctions, and a method for spectroscopic deconvolution of the overlapping G peaks of the SWNT and the SLG is reported, making use of the polarization dependence of the SWNT. A comparison of the Raman peak positions and intensities of the individual SWNT and graphene to those of the SWNT-graphene junction indicates an electron transfer of 1.12 × 10¹³ cm⁻² from the SWNT to the graphene. This direction of charge transfer is in agreement with the work functions of the SWNT and graphene. The compression of the SWNT by the graphene increases the broadening of the radial breathing mode (RBM) peak from 3.6 ± 0.3 to 4.6 ± 0.5 cm⁻¹ and of the G peak from 13 ± 1 to 18 ± 1 cm⁻¹, in reasonable agreement with molecular dynamics simulations. However, the RBM and G peak position shifts are primarily due to charge transfer with minimal contributions from strain. With this method, the ability to dope graphene with nanometer resolution is demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extreme daily increases in peak electricity demand: Tail-quantile estimation

International Nuclear Information System (INIS)

Sigauke, Caston; Verster, Andréhette; Chikobvu, Delson

2013-01-01

A Generalized Pareto Distribution (GPD) is used to model extreme daily increases in peak electricity demand. The model is fitted to years 2000–2011 recorded data for South Africa to make a comparative analysis with the Generalized Pareto-type (GP-type) distribution. Peak electricity demand is influenced by the tails of probability distributions as well as by means or averages. At times there is a need to depart from the average thinking and exploit information provided by the extremes (tails). Empirical results show that both the GP-type and the GPD are a good fit to the data. One of the main advantages of the GP-type is the estimation of only one parameter. Modelling of extreme daily increases in peak electricity demand helps in quantifying the amount of electricity which can be shifted from the grid to off peak periods. One of the policy implications derived from this study is the need for day-time use of electricity billing system similar to the one used in the cellular telephone/and fixed line-billing technology. This will result in the shifting of electricity demand on the grid to off peak time slots as users try to avoid high peak hour charges. - Highlights: ► Policy makers should design demand response strategies to save electricity. ► Peak electricity demand is influenced by tails of probability distributions. ► Both the GSP and the GPD are a good fit to the data. ► Accurate assessment of level and frequency of extreme load forecasts is important.

Application of a novel measure of EEG non-stationarity as 'Shannon- entropy of the peak frequency shifting' for detecting residual abnormalities in concussed individuals.

Science.gov (United States)

Cao, Cheng; Slobounov, Semyon

2011-07-01

The aim of this report was to propose a novel measure of non-stationarity of EEG signals, named Shannon- entropy of the peak frequency shifting (SEPFS). The feasibility of this method was documented comparing this measure with traditional time domain assessment of non-stationarity and its application to EEG data sets obtained from student-athletes before and after suffering a single episode of mild traumatic brain injury (mTBI) with age-matched normal controls. Instead of assessing the power density distribution on the time-frequency plane, like previously proposed measures of signal non-stationarity, this new measure is based on the shift of the dominant frequency of the EEG signal over time. We applied SEPFS measure to assess the properties of EEG non-stationarity in subjects before and shortly after they suffered mTBI. Student-athletes at high risk for mTBI (n=265) were tested prior to concussive episodes as a baseline. From this subject pool, 30 athletes who suffered from mTBI were retested on day 30 post-injury. Additional subjects pool (student-athletes without history of concussion, n=30) were recruited and test-re-tested within the same 30 day interval. Thirty-two channels EEG signals were acquired in sitting eyes closed condition. The results showed that the SEPFS values significantly decreased in subjects suffering from mTBI. Specifically, reduced EEG non-stationarity was observed in occipital, temporal and central brain areas, indicating the possibility of residual brain dysfunctions in concussed individuals. A similar but less statistically significant trend was observed using traditional time domain analysis of EEG non-stationarity. The proposed measure has at least two merits of interest: (1) it is less affected by the limited resolution of time-frequency representation of the EEG signal; (2) it takes into account the neural characteristics of the EEG signal that have not been considered in previously proposed measures of non-stationarity. This new

Isotope shifts in odd and even energy levels of the neutral and singly ionised gadolinium atom

International Nuclear Information System (INIS)

Ahmad, S.A.; Venugopalan, A.; Saksena, G.D.

1979-01-01

Isotope shift studies in the gadolinium spectra have been extended in the region 4140 to 4535 A. Isotope shift Δσ(156 to 160) have been measured in 315 lines of the neutral and singly ionised gadolinium atom using a recording Fabry-Perot Spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Some of the Gd I lines studied involve transitions from newly identified high odd levels of 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 5d 3 configurations to low even levels of 4f 8 6s 2 and 4f 7 6s 2 6p configurations. Electronic configurations of the energy levels have been discussed on the basis of observed isotope shifts. In some cases assigned configurations have been revised and probable configurations have been suggested. (author)

Growth of Au nanoparticle films and the effect of nanoparticle shape on plasmon peak wavelength

Energy Technology Data Exchange (ETDEWEB)

Horikoshi, S., E-mail: horikoshi@sstl.info; Matsumoto, N.; Kato, T. [Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo Bunkyo, Tokyo 113-8656 (Japan); Omata, Y. [Application and Technical Support, Elionix, Inc., 3-7-6 Motoyokoyama Hachioji, Tokyo 192-0063 (Japan)

2014-05-21

Metal nanoparticles (NPs) exhibit localized surface plasmon resonance (LSPR) and thus have potential for use in a wide range of applications. A facile technique for the preparation of NP films using an electron-cyclotron-resonance plasma sputtering method without a dewetting process is described. Field emission scanning electron microscopy (FE-SEM) observations revealed that the Au NPs grew independently as island-like particles during the first stage of sputtering and then coalesced with one another as sputtering time increased to ultimately form a continuous film. A plasmon absorption peak was observed via optical measurement of absorption efficiency. The LSPR peak shifted toward longer wavelengths (red shift) with an increase in sputtering time. The cause of this plasmon peak shift was theoretically investigated using the finite-difference time-domain calculation method. A realistic statistical distribution of the particle shapes based on FE-SEM observations was applied for the analysis, which has not been previously reported. It was determined that the change in the shape of the NPs from spheroidal to oval or slender due to coalescence with neighbouring NPs caused the LSPR peak shift. These results may enable the design of LSPR devices by controlling the characteristics of the nanoparticles, such as their size, shape, number density, and coverage.

Growth of Au nanoparticle films and the effect of nanoparticle shape on plasmon peak wavelength

Science.gov (United States)

Horikoshi, S.; Matsumoto, N.; Omata, Y.; Kato, T.

2014-05-01

Metal nanoparticles (NPs) exhibit localized surface plasmon resonance (LSPR) and thus have potential for use in a wide range of applications. A facile technique for the preparation of NP films using an electron-cyclotron-resonance plasma sputtering method without a dewetting process is described. Field emission scanning electron microscopy (FE-SEM) observations revealed that the Au NPs grew independently as island-like particles during the first stage of sputtering and then coalesced with one another as sputtering time increased to ultimately form a continuous film. A plasmon absorption peak was observed via optical measurement of absorption efficiency. The LSPR peak shifted toward longer wavelengths (red shift) with an increase in sputtering time. The cause of this plasmon peak shift was theoretically investigated using the finite-difference time-domain calculation method. A realistic statistical distribution of the particle shapes based on FE-SEM observations was applied for the analysis, which has not been previously reported. It was determined that the change in the shape of the NPs from spheroidal to oval or slender due to coalescence with neighbouring NPs caused the LSPR peak shift. These results may enable the design of LSPR devices by controlling the characteristics of the nanoparticles, such as their size, shape, number density, and coverage.

Optical and scintillating properties of Ce:Li(Y,Lu)F4 single crystals

International Nuclear Information System (INIS)

Yokota, Yuui; Kurosawa, Shunsuke; Chani, Valery; Kamada, Kei; Yoshikawa, Akira

2014-01-01

We have investigated the optical and scintillating properties of Lu co-doped Ce:LiYF 4 single crystals with various Lu content. In the transmittance and absorption spectra, the absorption peaks at 243 nm get systematically red shifted in contrast to the peaks at 197 and 200 nm which get blue shifted with the increase in Lu content. At the same time, emission peaks at 306 nm and 200 nm under 295 nm excitation also get red shifted. The decay time of Ce:Li(Y,Lu)F 4 crystals under 295 nm excitation is found to be faster than that of Ce:LiYF 4 and Ce:LiLuF 4 crystals. The alpha-peak positions in the pulse-height spectra and decay times of crystals under alpha-ray irradiation are found to vary with the Lu content. - Highlights: • Optical and scintillation properties of Ce:Li(Y 1-x Lu x )F 4 crystals were inspected. • Increase of Lu content resulted change of the position of four absorption peaks. • Admixing of Y and Lu decreased the light yield and increased the decay time. • The Ce:LiLuF 4 crystal indicated the largest light yield in the pulse-height spectra. • Li[(Y 0.8 Lu 0.2 ) 0.98 Ce 0.02 ]F 4 indicated larger light yield than Ce:LiYF 4 crystal

Asymmetry and the shift of the Compton profile

International Nuclear Information System (INIS)

Chatterjee, B.K.; Roy, S.C.; Suric, T.; LaJohn, L.A.; Pratt, R.H.

2007-01-01

We show that the conventionally defined asymmetry of the Compton profile (CP) is, to a large extent, simply a shift of CP. Compton scattering is widely used in studying the electron momentum distribution (EMD) of complex systems. Extraction of information about the EMD is based on an impulse approximation (IA) description of the process. In IA the scattering from bound electrons is described as scattering from the EMD of free electrons. Most often the angular and energy distributions of scattered photons (doubly differential cross sections (DDCS)) is measured and presented in terms of CP, which is just the DDCS normalized by a kinematical factor. The deviations of measured CP from the IA results are conventionally described as an asymmetry of CP about the IA peak position. IA predicts CP to be symmetric. We have examined the discrepancy between IA predictions (and the corresponding relativistic version of IA, RIA) and more rigorous approaches (A 2 and S-matrix), using independent particle approximations for the description of the bound state of electrons. In the nonrelativistic region (in which many measurements of CP are performed) we find that the conventional asymmetry can largely be understood as the shift of the peak position. The true asymmetry with respect to the shifted peak position is in fact much smaller. RIA has similar properties to IA, except that for atoms with high nuclear charge the p → .A → interaction may modify the shift and limit the utility of description as a shift

A single photon sensor employing wavelength-shifting and light-guiding technology

Energy Technology Data Exchange (ETDEWEB)

Schulte, Lukas; Voge, Markus; Boeser, Sebastian; Kowalski, Marek [Physikalisches Institut, Universitaet Bonn (Germany)

2013-07-01

In this work we describe a feasibility study of a novel type of single photon sensor that employs organic wavelength shifting materials (WLS) to capture photons and guide them to a PMT readout. Two different WLS materials, Saint Gobain BC-480 and BC-482A, have been tested as candidates for use in such a sensor. We address the photon detection efficiency, noise properties, time and spatial resolution, PMT readout, as well as some practical aspects relevant for the development and construction of a prototype sensor. Calculating the overall photon detection efficiency, we show that the effective photosensitive area of a prototype built with existing technology could easily exceed that of modules currently used e. g. in IceCube while having a dark noise rate up to two orders of magnitude smaller.

Islanding and strain-induced shifts in the infrared absorption peaks of cubic boron nitride thin films

International Nuclear Information System (INIS)

Fahy, S.; Taylor, C.A. II and; Clarke, R.

1997-01-01

Experimental and theoretical investigations of the infrared-active, polarization-dependent phonon frequencies of cubic boron nitride films have been performed in light of recent claims that large frequency shifts during initial nucleation are the result of strain caused by highly nonequilibrium growth conditions. We show that the formation of small, separate grains of cubic boron nitride during the initial growth leads to a frequency shift in the infrared-active transverse-optic mode, polarized normal to the substrate, which is opposite in sign and twice the magnitude of the shift for modes polarized parallel to the substrate. In contrast, film strain causes a frequency shift in the mode polarized normal to the substrate, which is much smaller in magnitude than the frequency shift for modes polarized parallel to the substrate. Normal and off-normal incidence absorption measurements, performed at different stages of nucleation and growth, show that large frequency shifts in the transverse-optic-phonon modes during the initial stage of growth are not compatible with the expected effects of strain, but are in large part due to nucleation of small isolated cubic BN grains which coalesce to form a uniform layer. Numerical results from a simple model of island nucleation and growth are in good agreement with experimental results. copyright 1997 The American Physical Society

Assessing peak aerobic capacity in Dutch law enforcement officers

NARCIS (Netherlands)

Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

2015-01-01

Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

Assessing peak aerobic capacity in Dutch law enforcement officers.

NARCIS (Netherlands)

Wittink, H.; Takken, T.; Groot, J.F. de; Reneman, M.; Peters, R.; Vanhees, L.

2015-01-01

Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

Analytical study of nonlinear phase shift through stimulated Brillouin scattering in single mode fiber with the pump power recycling technique

International Nuclear Information System (INIS)

Al-Asadi, H A; Mahdi, M A; Bakar, A A A; Adikan, F R Mahamd

2011-01-01

We present a theoretical study of nonlinear phase shift through stimulated Brillouin scattering in single mode optical fiber. Analytical expressions describing the nonlinear phase shift for the pump and Stokes waves in the pump power recycling technique have been derived. The dependence of the nonlinear phase shift on the optical fiber length, the reflectivity of the optical mirror and the frequency detuning coefficient have been analyzed for different input pump power values. We found that with the recycling pump technique, the nonlinear phase shift due to stimulated Brillouin scattering reduced to less than 0.1 rad for 5 km optical fiber length and 0.65 reflectivity of the optical mirror, respectively, at an input pump power equal to 30 mW

Conductance of single-atom platinum contacts: Voltage dependence of the conductance histogram

DEFF Research Database (Denmark)

Nielsen, S.K.; Noat, Y.; Brandbyge, Mads

2003-01-01

The conductance of a single-atom contact is sensitive to the coupling of this contact atom to the atoms in the leads. Notably for the transition metals this gives rise to a considerable spread in the observed conductance values. The mean conductance value and spread can be obtained from the first...... peak in conductance histograms recorded from a large set of contact-breaking cycles. In contrast to the monovalent metals, this mean value for Pt depends strongly on the applied voltage bias and other experimental conditions and values ranging from about 1 G(0) to 2.5 G(0) (G(0)=2e(2)/h) have been...... reported. We find that at low bias the first peak in the conductance histogram is centered around 1.5 G(0). However, as the bias increases past 300 mV the peak shifts to 1.8 G(0). Here we show that this bias dependence is due to a geometric effect where monatomic chains are replaced by single-atom contacts...

A novel peak detection approach with chemical noise removal using short-time FFT for prOTOF MS data.

Science.gov (United States)

Zhang, Shuqin; Wang, Honghui; Zhou, Xiaobo; Hoehn, Gerard T; DeGraba, Thomas J; Gonzales, Denise A; Suffredini, Anthony F; Ching, Wai-Ki; Ng, Michael K; Wong, Stephen T C

2009-08-01

Peak detection is a pivotal first step in biomarker discovery from MS data and can significantly influence the results of downstream data analysis steps. We developed a novel automatic peak detection method for prOTOF MS data, which does not require a priori knowledge of protein masses. Random noise is removed by an undecimated wavelet transform and chemical noise is attenuated by an adaptive short-time discrete Fourier transform. Isotopic peaks corresponding to a single protein are combined by extracting an envelope over them. Depending on the S/N, the desired peaks in each individual spectrum are detected and those with the highest intensity among their peak clusters are recorded. The common peaks among all the spectra are identified by choosing an appropriate cut-off threshold in the complete linkage hierarchical clustering. To remove the 1 Da shifting of the peaks, the peak corresponding to the same protein is determined as the detected peak with the largest number among its neighborhood. We validated this method using a data set of serial peptide and protein calibration standards. Compared with MoverZ program, our new method detects more peaks and significantly enhances S/N of the peak after the chemical noise removal. We then successfully applied this method to a data set from prOTOF MS spectra of albumin and albumin-bound proteins from serum samples of 59 patients with carotid artery disease compared to vascular disease-free patients to detect peaks with S/N> or =2. Our method is easily implemented and is highly effective to define peaks that will be used for disease classification or to highlight potential biomarkers.

Selective creation of colour centres and peaks of thermally stimulated luminescence by VUV photons in LiF single crystals

International Nuclear Information System (INIS)

Vasil'chenko, E.; Kudryavtseva, I.; Lushchik, A.; Lushchik, Ch.; Nagirnyi, V.

2005-01-01

Processes of radiation creation and annealing of Frenkel defects as well as electron-hole processes have been studied in LiF single crystals with a various content of impurity ions by means of highly sensitive method of thermally stimulated luminescence (TSL) and other optical methods. In highly pure LiF crystals, X-irradiated at 4.2 K, the TSL peaks connected with the annealing of interstitial fluorine ions (25-40 K) or atoms, i.e. H centres (50-65 K) and self-trapped holes (120-140 K) have been separated. For the first time, the creation spectra of the TSL peaks at 480 and 550 K by 10-33 eV-photon irradiation at 295 K have been measured. The anomalously high creation efficiency of the TSL peak at 480 K by 11.7-12.3 eV and 26-27 eV photons is interpreted as the creation of near-impurity electronic excitations both, directly by photons and by hot conduction electrons. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Lateral shift in one-dimensional quasiperiodic chiral photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Da, Jian, E-mail: dajian521@sina.com [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Mo, Qi, E-mail: moqiyueyang@163.com [School of Software, Yunnan University, Cuihu Bai Road, Kunming City, Yunnan Province 650091 (China); Cheng, Yaokun [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Liu, Taixiang [Taishan Vocational College of Nursing, Shandong Province 271000 (China)

2015-02-01

We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.

Effects of temperature and other experimental variables on single molecule vibrational spectroscopy with the scanning tunneling microscope

International Nuclear Information System (INIS)

Lauhon, L. J.; Ho, W.

2001-01-01

Inelastic electron tunneling spectroscopy (IETS) was performed on single molecules with a variable temperature scanning tunneling microscope. The peak intensity, width, position, and line shape of single molecule vibrational spectra were studied as a function of temperature, modulation bias, bias polarity, and tip position for the (C--H,C--D) stretching vibration of acetylene (C 2 H 2 ,C 2 D 2 ) on Cu(001). The temperature broadening of vibrational peaks was found to be a consequence of Fermi smearing as in macroscopic IETS. The modulation broadening of vibrational peaks assumed the expected form for IETS. Extrapolation of the peak width to zero temperature and modulation suggested an intrinsic width of ∼4 meV due primarily to instrumental broadening. The inelastic tunneling cross section at negative bias was reduced by a factor of 1.7 for the C--H stretch mode. Low energy modes of other molecules did not show such a reduction. There was no evidence of a tip-induced Stark shift in the peak positions. The spatial variation of the inelastic signal was measured to determine the junction stability necessary for the acquisition of single molecule vibrational spectra

Impedance self-matching ultra-narrow linewidth fiber resonator by use of a tunable π-phase-shifted FBG.

Science.gov (United States)

Jing, Mingyong; Yu, Bo; Hu, Jianyong; Hou, Huifang; Zhang, Guofeng; Xiao, Liantuan; Jia, Suotang

2017-05-15

In this paper, we present a novel ultra-narrow linewidth fiber resonator formed by a tunable polarization maintaining (PM) π-phase-shifted fiber Bragg grating and a PM uniform fiber Bragg grating with a certain length of PM single mode fiber patch cable between them. Theoretical prediction shows that this resonator has ultra-narrow linewidth resonant peaks and is easy to realize impedance matching. We experimentally obtain 3 MHz narrow linewidth impedance matched resonant peak in a 7.3 m ultra-long passive fiber cavity. The impedance self-matching characteristic of this resonator also makes itself particularly suitable for use in ultra-sensitive sensors, ultra-narrow band rejection optical filters and fiber lasers applications.

Design of all-optical high-order temporal integrators based on multiple-phase-shifted Bragg gratings.

Science.gov (United States)

Asghari, Mohammad H; Azaña, José

2008-07-21

In exact analogy with their electronic counterparts, photonic temporal integrators are fundamental building blocks for constructing all-optical circuits for ultrafast information processing and computing. In this work, we introduce a simple and general approach for realizing all-optical arbitrary-order temporal integrators. We demonstrate that the N(th) cumulative time integral of the complex field envelope of an input optical waveform can be obtained by simply propagating this waveform through a single uniform fiber/waveguide Bragg grating (BG) incorporating N pi-phase shifts along its axial profile. We derive here the design specifications of photonic integrators based on multiple-phase-shifted BGs. We show that the phase shifts in the BG structure can be arbitrarily located along the grating length provided that each uniform grating section (sections separated by the phase shifts) is sufficiently long so that its associated peak reflectivity reaches nearly 100%. The resulting designs are demonstrated by numerical simulations assuming all-fiber implementations. Our simulations show that the proposed approach can provide optical operation bandwidths in the tens-of-GHz regime using readily feasible photo-induced fiber BG structures.

A new automatic fixed peak technology of microcontroller

International Nuclear Information System (INIS)

Huang Liguo; Wang Dequan; Zhang Damin; Li Jun; Liu Yuwen; Guo Qingxue; Wang Guifeng

1999-01-01

The microcontroller automatic fixed peak technology which differs from fashion half channel fixed peak is described. It bases on the principles of selecting double single channel and readjusting the voltage of power source. This technology is suitable to the industrial isotope instruments with various radioactive sources

Small-Signal Analysis of Single-Phase and Three-phase DC/AC and AC/DC PWM Converters with the Frequency-Shift Technique

DEFF Research Database (Denmark)

Blaabjerg, Frede; Aquila, A. Dell’; Liserre, Marco

2004-01-01

of dc/dc converters via a 50 Hz frequency-shift. The input admittance is calculated and measured for two study examples (a three-phase active rectifier and a single-phase photovoltaic inverter). These examples show that the purpose of a well designed controller for grid-connected converters......A systematic approach to study dc/ac and ac/dc converters without the use of synchronous transformation is proposed. The use of a frequency-shift technique allows a straightforward analysis of single-phase and three-phase systems. The study of dc/ac and of ac/dc converters is reported to the study...... is to minimize the input admittance in order to make the grid converter more robust to grid disturbance....

Optical absorption of zigzag single walled boron nitride nanotubes

Science.gov (United States)

Moradian, Rostam; Chegel, Raad; Behzad, Somayeh

2010-11-01

In a realistic three-dimensional model, optical matrix element and linear optical absorption of zigzag single walled boron nitride nanotubes (BNNTs) in the tight binding approximation are studied. In terms of absolute value of dipole matrix elements of the first three direct transitions at kz=0, we divided the zigzag BNNTs into three groups and investigated their optical absorption spectrum in energy ranges E7.5 eV. We found that in lower energies, E7.5 eV, their behaviors depend on their even or odd nanotube index. We also found that in the energy range 7peaks denoted by ‘A’ and ‘B’ where the ‘B’ peak energy position is approximately constant and is independent of the nanotube diameter. We also found that increasing the tubes diameter leads to red shift for all peaks except ‘A’ peak where this peak moves to higher energies. Our results are in good agreement with the experimental results.

Precision in single atom localization via Raman-driven coherence: Role of detuning and phase shift

Energy Technology Data Exchange (ETDEWEB)

Rahmatullah,; Qamar, Sajid, E-mail: sajid_qamar@comsats.edu.pk

2013-10-01

Role of detuning and phase shift associated with the standing-wave driving fields is revisited for precision position measurement of single atom during its motion through two standing-wave fields. A four-level atomic system in diamond configuration is considered where the intermediate levels are coupled to upper and lower level via standing-wave driving fields and atomic decay channels, respectively. The former is responsible for the generation of quantum mechanical coherence via two-photon Raman transition while the latter leads to spontaneous emission of a photon. Due to standing-wave driving fields the atom–field interaction becomes position-dependent and measurement of the frequency of spontaneously emitted photon gives the position information of the atom. The unique position of the atom with much higher spatial resolution, i.e., of the order of λ/100 is observed using detuning and phase shift associated with the standing-wave driving fields.

High fat diet promotes achievement of peak bone mass in young rats

Energy Technology Data Exchange (ETDEWEB)

Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Mittal, Monika; Chattopadhyay, Naibedya [Division of Endocrinology and Center for Research in Anabolic Skeletal Targets in Health and Illness (ASTHI), CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226 031 (India); Wani, Mohan R. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Bhat, Manoj Kumar, E-mail: manojkbhat@nccs.res.in [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India)

2014-12-05

Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

High fat diet promotes achievement of peak bone mass in young rats

International Nuclear Information System (INIS)

Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T.; Mittal, Monika; Chattopadhyay, Naibedya; Wani, Mohan R.; Bhat, Manoj Kumar

2014-01-01

Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet

From Modeling of Plasticity in Single-Crystal Superalloys to High-Resolution X-rays Three-Crystal Diffractometer Peaks Simulation

Science.gov (United States)

Jacques, Alain

2016-12-01

The dislocation-based modeling of the high-temperature creep of two-phased single-crystal superalloys requires input data beyond strain vs time curves. This may be obtained by use of in situ experiments combining high-temperature creep tests with high-resolution synchrotron three-crystal diffractometry. Such tests give access to changes in phase volume fractions and to the average components of the stress tensor in each phase as well as the plastic strain of each phase. Further progress may be obtained by a new method making intensive use of the Fast Fourier Transform, and first modeling the behavior of a representative volume of material (stress fields, plastic strain, dislocation densities…), then simulating directly the corresponding diffraction peaks, taking into account the displacement field within the material, chemical variations, and beam coherence. Initial tests indicate that the simulated peak shapes are close to the experimental ones and are quite sensitive to the details of the microstructure and to dislocation densities at interfaces and within the soft γ phase.

[An automatic peak detection method for LIBS spectrum based on continuous wavelet transform].

Science.gov (United States)

Chen, Peng-Fei; Tian, Di; Qiao, Shu-Jun; Yang, Guang

2014-07-01

Spectrum peak detection in the laser-induced breakdown spectroscopy (LIBS) is an essential step, but the presence of background and noise seriously disturb the accuracy of peak position. The present paper proposed a method applied to automatic peak detection for LIBS spectrum in order to enhance the ability of overlapping peaks searching and adaptivity. We introduced the ridge peak detection method based on continuous wavelet transform to LIBS, and discussed the choice of the mother wavelet and optimized the scale factor and the shift factor. This method also improved the ridge peak detection method with a correcting ridge method. The experimental results show that compared with other peak detection methods (the direct comparison method, derivative method and ridge peak search method), our method had a significant advantage on the ability to distinguish overlapping peaks and the precision of peak detection, and could be be applied to data processing in LIBS.

Peak effect in twinned superconductors

International Nuclear Information System (INIS)

Larkin, A.I.; Marchetti, M.C.; Vinokur, V.M.

1995-01-01

A sharp maximum in the critical current J c as a function of temperature just below the melting point of the Abrikosov flux lattice has recently been observed in both low- and high-temperature superconductors. This peak effect is strongest in twinned crystals for fields aligned with the twin planes. We propose that this peak signals the breakdown of the collective pinning regime and the crossover to strong pinning of single vortices on the twin boundaries. This crossover is very sharp and can account for the steep drop of the differential resistivity observed in experiments. copyright 1995 The American Physical Society

Soft theorems for shift-symmetric cosmologies

Science.gov (United States)

Finelli, Bernardo; Goon, Garrett; Pajer, Enrico; Santoni, Luca

2018-03-01

We derive soft theorems for single-clock cosmologies that enjoy a shift symmetry. These so-called consistency conditions arise from a combination of a large diffeomorphism and the internal shift symmetry and fix the squeezed limit of all correlators with a soft scalar mode. As an application, we show that our results reproduce the squeezed bispectrum for ultra-slow-roll inflation, a particular shift-symmetric, nonattractor model which is known to violate Maldacena's consistency relation. Similar results have been previously obtained by Mooij and Palma using background-wave methods. Our results shed new light on the infrared structure of single-clock cosmological spacetimes.

Neuroscience imaging enabled by new highly tunable and high peak power femtosecond lasers

Science.gov (United States)

Hakulinen, T.; Klein, J.

2017-02-01

Neuroscience applications benefit from recent developments in industrial femtosecond laser technology. New laser sources provide several megawatts of peak power at wavelength of 1040 nm, which enables simultaneous optogenetics photoactivation of tens or even hundreds of neurons using red shifted opsins. Another recent imaging trend is to move towards longer wavelengths, which would enable access to deeper layers of tissue due to lower scattering and lower absorption in the tissue. Femtosecond lasers pumping a non-collinear optical parametric amplifier (NOPA) enable the access to longer wavelengths with high peak powers. High peak powers of >10 MW at 1300 nm and 1700 nm allow effective 3-photon excitation of green and red shifted calcium indicators respectively and access to deeper, sub-cortex layers of the brain. Early results include in vivo detection of spontaneous activity in hippocampus within an intact mouse brain, where neurons express GCaMP6 activated in a 3-photon process at 1320 nm.

Analysis of neutron diffraction peak broadening caused by internal stresses in composite materials

International Nuclear Information System (INIS)

Todd, R.I.; Borsa, C.; Derby, B.

1994-01-01

Neutron diffraction is an essential tool in the study of internal stresses in composite materials. In most work only the peak shifts caused by the related elastic strains are considered, but other valuable information exists in the form of peak shape changes. The conditions under which the pure diffraction profile of the composite (i.e. the profile when all sources of broadening not caused by the residual stresses are removed) represents the probability distribution of the peak shifts corresponding to the strains are examined. It is shown that in these conditions, the pure diffraction profile has no attributes of particle size broadening (and vice versa), thereby providing a test for the validity of results interpreted in this way. The experimental derivation of measured strain distributions in Al 2 O 3 /SiCp composites using neutron diffraction is described. No apparent particle size broadening was detected, demonstrating the validity of the results, which also satisfied other tests for consistency

Using chemical shift perturbation to characterise ligand binding.

Science.gov (United States)

Williamson, Mike P

2013-08-01

Chemical shift perturbation (CSP, chemical shift mapping or complexation-induced changes in chemical shift, CIS) follows changes in the chemical shifts of a protein when a ligand is added, and uses these to determine the location of the binding site, the affinity of the ligand, and/or possibly the structure of the complex. A key factor in determining the appearance of spectra during a titration is the exchange rate between free and bound, or more specifically the off-rate koff. When koff is greater than the chemical shift difference between free and bound, which typically equates to an affinity Kd weaker than about 3μM, then exchange is fast on the chemical shift timescale. Under these circumstances, the observed shift is the population-weighted average of free and bound, which allows Kd to be determined from measurement of peak positions, provided the measurements are made appropriately. (1)H shifts are influenced to a large extent by through-space interactions, whereas (13)Cα and (13)Cβ shifts are influenced more by through-bond effects. (15)N and (13)C' shifts are influenced both by through-bond and by through-space (hydrogen bonding) interactions. For determining the location of a bound ligand on the basis of shift change, the most appropriate method is therefore usually to measure (15)N HSQC spectra, calculate the geometrical distance moved by the peak, weighting (15)N shifts by a factor of about 0.14 compared to (1)H shifts, and select those residues for which the weighted shift change is larger than the standard deviation of the shift for all residues. Other methods are discussed, in particular the measurement of (13)CH3 signals. Slow to intermediate exchange rates lead to line broadening, and make Kd values very difficult to obtain. There is no good way to distinguish changes in chemical shift due to direct binding of the ligand from changes in chemical shift due to allosteric change. Ligand binding at multiple sites can often be characterised, by

Abdominal Hollowing Reduces Lateral Trunk Displacement During Single-Leg Squats in Healthy Females But Does Not Affect Peak Hip Abduction Angle or Knee Abductio Angle/Moment.

Science.gov (United States)

Linde, Lukas D; Archibald, Jessica; Lampert, Eve C; Srbely, John Z

2017-07-17

Females suffer 4-6 times more non-contact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Interventional Study Setting: Movement and Posture Laboratory Participants: 13 healthy females (21.3±0.88y, 1.68±0.07m, 58.27±5.46kg) Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, control), confirmed via surface electromyography. Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. No differences were observed for peak lateral trunk displacement, peak hip adduction angle or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in four of six muscles recorded. The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

On the counting rate-dependent amplitude shifts in proportional counters

International Nuclear Information System (INIS)

Mahesh, K.

1976-01-01

The presence of a positive ion cloud near the anode wire, which has been believed to be the cause of the observed counting rate-dependent peak shifts in proportional counters, does not explain various exhibited features of these shifts. The possibility of other mechanisms involved is, therefore, examined. The columnar recombination of primary ions in the counter is considered to explain the origin of the shifts and their observed features. (Auth.)

An analysis of Chinas CO2 emission peaking target and pathways

OpenAIRE

He, Jian-Kun

2017-01-01

China has set the goal for its CO2 emissions to peak around 2030, which is not only a strategic decision coordinating domestic sustainable development and global climate change mitigation but also an overarching target and a key point of action for Chinas resource conservation, environmental protection, shift in economic development patterns, and CO2 emission reduction to avoid climate change. The development stage where China maps out the CO2 emission peak target is earlier than that of the ...

The slightly-enriched spectral shift control reactor

Energy Technology Data Exchange (ETDEWEB)

Martin, W.R.; Lee, J.C.; Larsen, E.W. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering); Edlund, M.C. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical and Nuclear Engineering)

1991-11-01

An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile {sup 238}U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC.

The slightly-enriched spectral shift control reactor

International Nuclear Information System (INIS)

Martin, W.R.; Lee, J.C.; Larsen, E.W.; Edlund, M.C.

1991-11-01

An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile 238 U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC

Modelling the acid/base 1H NMR chemical shift limits of metabolites in human urine.

Science.gov (United States)

Tredwell, Gregory D; Bundy, Jacob G; De Iorio, Maria; Ebbels, Timothy M D

2016-01-01

Despite the use of buffering agents the 1 H NMR spectra of biofluid samples in metabolic profiling investigations typically suffer from extensive peak frequency shifting between spectra. These chemical shift changes are mainly due to differences in pH and divalent metal ion concentrations between the samples. This frequency shifting results in a correspondence problem: it can be hard to register the same peak as belonging to the same molecule across multiple samples. The problem is especially acute for urine, which can have a wide range of ionic concentrations between different samples. To investigate the acid, base and metal ion dependent 1 H NMR chemical shift variations and limits of the main metabolites in a complex biological mixture. Urine samples from five different individuals were collected and pooled, and pre-treated with Chelex-100 ion exchange resin. Urine samples were either treated with either HCl or NaOH, or were supplemented with various concentrations of CaCl 2 , MgCl 2 , NaCl or KCl, and their 1 H NMR spectra were acquired. Nonlinear fitting was used to derive acid dissociation constants and acid and base chemical shift limits for peaks from 33 identified metabolites. Peak pH titration curves for a further 65 unidentified peaks were also obtained for future reference. Furthermore, the peak variations induced by the main metal ions present in urine, Na + , K + , Ca 2+ and Mg 2+ , were also measured. These data will be a valuable resource for 1 H NMR metabolite profiling experiments and for the development of automated metabolite alignment and identification algorithms for 1 H NMR spectra.

Parameter selection for peak alignment in chromatographic sample profiling: Objective quality indicators and use of control samples

NARCIS (Netherlands)

Peters, S.; van Velzen, E.; Janssen, H.-G.

2009-01-01

In chromatographic profiling applications, peak alignment is often essential as most chromatographic systems exhibit small peak shifts over time. When using currently available alignment algorithms, there are several parameters that determine the outcome of the alignment process. Selecting the

Fringe-shifting single-projector moiré topography application for cotyle implantate abrasion measurement

Science.gov (United States)

Rössler, Tomáš; Hrabovský, Miroslav; Pluháček, František

2005-08-01

The cotyle implantate is abraded in the body of patient and its shape changes. Information about the magnitude of abrasion is contained in the result contour map of the implantate. The locations and dimensions of abraded areas can be computed from the contours deformation. The method called the single-projector moire topography was used for the contour lines determination. The theoretical description of method is given at first. The design of the experimental set-up follows. The light grating projector was developed to realize the periodic structure on the measured surface. The method of fringe-shifting was carried out to increase the data quantity. The description of digital processing applied to the moire grating images is introduced at the end together with the examples of processed images.

Study of energy transfer in single and multi-emissive layer using Gaussian peak fitting

International Nuclear Information System (INIS)

Yoon, Ju-An; Kim, You-Hyun; Kim, Nam Ho; Moon, Chang-Bum; He, Gufeng; Kim, Woo Young

2014-01-01

White organic light-emitting diodes(WOLEDs) were fabricated with the device structure of ITO(1800 Å)/NPB(700 Å)/emissive layer(300 Å)/Bphen(300 Å)/Liq(20 Å)/Al(1200 Å) using the two complementary colors method. Then, we investigated their electrical and optical characteristics to determine luminous efficiency, luminance and color coordinates of single, double, triple and quadruple emissive layered-WOLED. Thickness of emissive layer was fixed at 30 Å, and DPASN and BAlq were used for blue emissive host material and DCJTB was added as red dopant in the emissive layer. Then, we investigated the performance of OLEDs via its charge blocking structure and its different emissive region with emissive layers. Luminous efficiency of 5.30 cd/A at 50 mA/cm 2 of current density is obtained in WOLED device with double emissive layer of DPASN:DCJTB-0.1% (150 Å)/BAlq:DCJTB-0.1% (150 Å) and these are 80% higher than WOLED device with single emissive layer of DPASN:DCJTB-0.1% (300 Å). - Highlights: • White OLEDs with multiple-emissive layer were fabricated using p- and n-type emissive materials. • We fabricated WOLEDs only using a small quantity of fluorescent red dopant materials. • The spectroscopic analysis using multi-peak fits with a Gaussian function. • The explain electroluminescence spectra of white OLEDs with the multiple-emissive layer. • We examine changes in the number of emissive layer about white OLEDs performance

Phase-shifted fiber Bragg grating inscription by fusion splicing technique and femtosecond laser

Science.gov (United States)

Jiang, Yajun; Yuan, Yuan; Xu, Jian; Yang, Dexing; Li, Dong; Wang, Meirong; Zhao, Jianlin

2016-11-01

A new method for phase-shifted fiber Bragg grating (PS-FBG) inscription in single mode fiber by fusion splicing technique and femtosecond laser is presented. The PS-FBG is produced by exposing the fusion spliced fiber with femtosecond laser through a uniform phase mask. The transmission spectrum of the PS-FBG shows a nonlinear red shift during the inscription process, and two or three main dips can be observed due to the formation of one or two FBG-based Fabry-Pérot structures by controlling the exposure intensity and time of the laser. For a peak power density of 4.8×1013 W/cm2, the induced refractive index modulation can reach to 6.3×10-4 in the fiber without sensitization. The PS-FBG's temperature, strain and pressure characteristics are also experimentally studied. These PS-FBGs can be potentially used for multiple wavelength fiber lasers, filters and optical fiber sensors.

Simultaneous collection method of on-peak window image and off-peak window image in Tl-201 imaging

International Nuclear Information System (INIS)

Murakami, Tomonori; Noguchi, Yasushi; Kojima, Akihiro; Takagi, Akihiro; Matsumoto, Masanori

2007-01-01

Tl-201 imaging detects the photopeak (71 keV, in on-peak window) of characteristic X-rays of Hg-201 formed from Tl-201 decay. The peak is derived from 4 rays of different energy and emission intensity and does not follow in Gaussian distribution. In the present study, authors made an idea for the method in the title to attain the more effective single imaging, which was examined for its accuracy and reliability with phantoms and applied clinically to Tl-201 scintigraphy in a patient. The authors applied the triple energy window method for data acquisition: the energy window setting was made on Hg-201 X-rays photopeak in three of the lower (3%, L), main (72 keV, M) and upper (14%, U) windows with the gamma camera with 2-gated detector (Toshiba E. CAM/ICON). L, M and U images obtained simultaneously were then constructed to images of on-peak (L+M, Mock on-peak) and off-peak (M+U) window settings for evaluation. Phantoms for line source with Tl-201-containing swab and for multi-defect with acrylic plate containing Tl-201 solution were imaged in water. The female patient with thyroid cancer was subjected to preoperative scintigraphy under the defined conditions. Mock on-, off-peak images were found to be equivalent to the true (ordinary, clinical) on-, off-peak ones, and the present method was thought usable for evaluation of usefulness of off-peak window data. (R.T.)

Performance of Differential-Phase-Shift Keying Protocol Applying 1310 nm Up-Conversion Single-Photon Detector

International Nuclear Information System (INIS)

Chen-Xu, Feng; Rong-Zhen, Jiao; Wen-Han, Zhang

2008-01-01

The performance of the differential-phase-shift keying (DPSK) protocol applying a 1310 nm up-conversion single-photon detector is analysed. The error rate and the communication rate as a function of distance for three quantum key distribution protocols, the Bennett–Brassard 1984, the Bennett–Brassard–Mermin 1992, and the DPSK, are presented. Then we compare the performance of these three protocols using the 1310nm up-conversion detector. We draw the conclusion that the DPSK protocol applying the detector has significant advantage over the other two protocols. Longer transmission distance and lower error rate can be achieved. (general)

All-optical Hilbert transformer based on a single phase-shifted fiber Bragg grating: design and analysis.

Science.gov (United States)

Asghari, Mohammad H; Azaña, José

2009-02-01

A simple all-fiber design for implementing an all-optical temporal Hilbert transformer is proposed and numerically demonstrated. We show that an all-optical Hilbert transformer can be implemented using a uniform-period fiber Bragg grating (FBG) with a properly designed amplitude-only grating apodization profile incorporating a single pi phase shift in the middle of the grating length. All-optical Hilbert transformers capable of processing arbitrary optical waveforms with bandwidths up to a few hundreds of gigahertz can be implemented using feasible FBGs.

Shift Work, Chronotype, and Melatonin Patterns among Female Hospital Employees on Day and Night Shifts.

Science.gov (United States)

Leung, Michael; Tranmer, Joan; Hung, Eleanor; Korsiak, Jill; Day, Andrew G; Aronson, Kristan J

2016-05-01

Shift work-related carcinogenesis is hypothesized to be mediated by melatonin; however, few studies have considered the potential effect modification of this underlying pathway by chronotype or specific aspects of shift work such as the number of consecutive nights in a rotation. In this study, we examined melatonin patterns in relation to shift status, stratified by chronotype and number of consecutive night shifts, and cumulative lifetime exposure to shift work. Melatonin patterns of 261 female personnel (147 fixed-day and 114 on rotations, including nights) at Kingston General Hospital were analyzed using cosinor analysis. Urine samples were collected from all voids over a 48-hour specimen collection period for measurement of 6-sulfatoxymelatonin concentrations using the Buhlmann ELISA Kit. Chronotypes were assessed using mid-sleep time (MSF) derived from the Munich Chronotype Questionnaire (MCTQ). Sociodemographic, health, and occupational information were collected by questionnaire. Rotational shift nurses working nights had a lower mesor and an earlier time of peak melatonin production compared to day-only workers. More pronounced differences in mesor and acrophase were seen among later chronotypes, and shift workers working ≥3 consecutive nights. Among nurses, cumulative shift work was associated with a reduction in mesor. These results suggest that evening-types and/or shift workers working ≥3 consecutive nights are more susceptible to adverse light-at-night effects, whereas long-term shift work may also chronically reduce melatonin levels. Cumulative and current exposure to shift work, including nights, affects level and timing of melatonin production, which may be related to carcinogenesis and cancer risk. Cancer Epidemiol Biomarkers Prev; 25(5); 830-8. ©2016 AACR. ©2016 American Association for Cancer Research.

Single peak parameters technique for simultaneous measurements: Spectrophotometric sequential injection determination of Fe(II) and Fe(III).

Science.gov (United States)

Kozak, J; Paluch, J; Węgrzecka, A; Kozak, M; Wieczorek, M; Kochana, J; Kościelniak, P

2016-02-01

Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of a single peak. In the developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into a holding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming a more stable colorless compound with Fe(III), a complex signal is registered. Measurements are performed at wavelength 530 nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2 min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04-4.00 and 0.1-5.00 mg L(-1), with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09 mg L(-1) for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Increased and mistimed sex hormone production in night shift workers.

Science.gov (United States)

Papantoniou, Kyriaki; Pozo, Oscar J; Espinosa, Ana; Marcos, Josep; Castaño-Vinyals, Gemma; Basagaña, Xavier; Juanola Pagès, Elena; Mirabent, Joan; Martín, Jordi; Such Faro, Patricia; Gascó Aparici, Amparo; Middleton, Benita; Skene, Debra J; Kogevinas, Manolis

2015-05-01

Night shift work has been associated with an increased risk for breast and prostate cancer. The effect of circadian disruption on sex steroid production is a possible underlying mechanism, underinvestigated in humans. We have assessed daily rhythms of sex hormones and melatonin in night and day shift workers of both sexes. We recruited 75 night and 42 day workers, ages 22 to 64 years, in different working settings. Participants collected urine samples from all voids over 24 hours on a working day. Urinary concentrations of 16 sex steroid hormones and metabolites (estrogens, progestagens, and androgens) and 6-sulfatoxymelatonin were measured in all samples. Mean levels and peak time of total and individual metabolite production were compared between night and day workers. Night workers had higher levels of total progestagens [geometric mean ratio (GMR) 1.65; 95% confidence intervals (CI), 1.17-2.32] and androgens (GMR: 1.44; 95% CI, 1.03-2.00), compared with day workers, after adjusting for potential confounders. The increased sex hormone levels among night shift workers were not related to the observed suppression of 6-sulfatoxymelatonin. Peak time of androgens was significantly later among night workers, compared with day workers (testosterone: 12:14 hours; 10:06-14:48 vs. 08:35 hours; 06:52-10:46). We found increased levels of progestagens and androgens as well as delayed peak androgen production in night shift workers compared with day workers. The increase and mistiming of sex hormone production may explain part of the increased risk for hormone-related cancers observed in night shift workers. ©2015 American Association for Cancer Research.

Quantitative estimation of infarct size by simultaneous dual radionuclide single photon emission computed tomography: comparison with peak serum creatine kinase activity

International Nuclear Information System (INIS)

Kawaguchi, K.; Sone, T.; Tsuboi, H.; Sassa, H.; Okumura, K.; Hashimoto, H.; Ito, T.; Satake, T.

1991-01-01

To test the hypothesis that simultaneous dual energy single photon emission computed tomography (SPECT) with technetium-99m (99mTc) pyrophosphate and thallium-201 (201TI) can provide an accurate estimate of the size of myocardial infarction and to assess the correlation between infarct size and peak serum creatine kinase activity, 165 patients with acute myocardial infarction underwent SPECT 3.2 +/- 1.3 (SD) days after the onset of acute myocardial infarction. In the present study, the difference in the intensity of 99mTc-pyrophosphate accumulation was assumed to be attributable to difference in the volume of infarcted myocardium, and the infarct volume was corrected by the ratio of the myocardial activity to the osseous activity to quantify the intensity of 99mTc-pyrophosphate accumulation. The correlation of measured infarct volume with peak serum creatine kinase activity was significant (r = 0.60, p less than 0.01). There was also a significant linear correlation between the corrected infarct volume and peak serum creatine kinase activity (r = 0.71, p less than 0.01). Subgroup analysis showed a high correlation between corrected volume and peak creatine kinase activity in patients with anterior infarctions (r = 0.75, p less than 0.01) but a poor correlation in patients with inferior or posterior infarctions (r = 0.50, p less than 0.01). In both the early reperfusion and the no reperfusion groups, a good correlation was found between corrected infarct volume and peak serum creatine kinase activity (r = 0.76 and r = 0.76, respectively; p less than 0.01)

Assessing the measurement of aerosol single scattering albedo by Cavity Attenuated Phase-Shift Single Scattering Monitor (CAPS PMssa)

Science.gov (United States)

Perim de Faria, Julia; Bundke, Ulrich; Onasch, Timothy B.; Freedman, Andrew; Petzold, Andreas

2016-04-01

The necessity to quantify the direct impact of aerosol particles on climate forcing is already well known; assessing this impact requires continuous and systematic measurements of the aerosol optical properties. Two of the main parameters that need to be accurately measured are the aerosol optical depth and single scattering albedo (SSA, defined as the ratio of particulate scattering to extinction). The measurement of single scattering albedo commonly involves the measurement of two optical parameters, the scattering and the absorption coefficients. Although there are well established technologies to measure both of these parameters, the use of two separate instruments with different principles and uncertainties represents potential sources of significant errors and biases. Based on the recently developed cavity attenuated phase shift particle extinction monitor (CAPS PM_{ex) instrument, the CAPS PM_{ssa instrument combines the CAPS technology to measure particle extinction with an integrating sphere capable of simultaneously measuring the scattering coefficient of the same sample. The scattering channel is calibrated to the extinction channel, such that the accuracy of the single scattering albedo measurement is only a function of the accuracy of the extinction measurement and the nephelometer truncation losses. This gives the instrument an accurate and direct measurement of the single scattering albedo. In this study, we assess the measurements of both the extinction and scattering channels of the CAPS PM_{ssa through intercomparisons with Mie theory, as a fundamental comparison, and with proven technologies, such as integrating nephelometers and filter-based absorption monitors. For comparison, we use two nephelometers, a TSI 3563 and an Aurora 4000, and two measurements of the absorption coefficient, using a Particulate Soot Absorption Photometer (PSAP) and a Multi Angle Absorption Photometer (MAAP). We also assess the indirect absorption coefficient

Noninvasive diagnosis of oral cancer by Stokes shift spectroscopy

Science.gov (United States)

Ebenezar, Jeyasingh; Ganesan, Singaravelu; Aruna, Prakasrao; Muralinaidu, Radhakrishnan

2014-03-01

The objective of this study is to evaluate the diagnostic potential of stokes shift (SS) spectroscopy (S3) for normal, precancer and cancerous oral lesions in vivo. The SS spectra were recorded in the 250 - 650 nm spectral range by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological oral lesions observed around 300, 355, 395, and 420 nm which are attributed to tryptophan, collagen, and NADH respectively. Using S3 technique one can obtain the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological oral lesions are verified by different ratio parameters.

Enhanced vegetation growth peak and its key mechanisms

Science.gov (United States)

Huang, K.; Xia, J.; Wang, Y.; Ahlström, A.; Schwalm, C.; Huntzinger, D. N.; Chen, J.; Cook, R. B.; Fang, Y.; Fisher, J. B.; Jacobson, A. R.; Michalak, A.; Schaefer, K. M.; Wei, Y.; Yan, L.; Luo, Y.

2017-12-01

It remains unclear that whether and how the vegetation growth peak has been shifted globally during the past three decades. Here we used two global datasets of gross primary productivity (GPP) and a satellite-derived Normalized Difference Vegetation Index (NDVI) to characterize recent changes in seasonal peak vegetation growth. The attribution of changes in peak growth to their driving factors was examined with several datasets. We demonstrated that the growth peak of global vegetation has been linearly increasing during the past three decades. About 65% of this trend is evenly explained by the expanding croplands (21%), rising atmospheric [CO2] (22%), and intensifying nitrogen deposition (22%). The contribution of expanding croplands to the peak growth trend was substantiated by measurements from eddy-flux towers, sun-induced chlorophyll fluorescence and a global database of plant traits, all of which demonstrated that croplands have a higher photosynthetic capacity than other vegetation types. The contribution of rising atmospheric [CO2] and nitrogen deposition are consistent with the positive response of leaf growth to elevated [CO2] (25%) and nitrogen addition (8%) from 346 manipulated experiments. The positive effect of rising atmospheric [CO2] was also well captured by 15 terrestrial biosphere models. However, most models underestimated the contributions of land-cover change and nitrogen deposition, but overestimated the positive effect of climate change.

Diffraction peaks in x-ray spectroscopy: Friend or foe?

International Nuclear Information System (INIS)

Tissot, R.G.; Goehner, R.P.

1992-01-01

Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra. In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample

Photoluminescence and Raman spectroscopy of single diamond nanoparticle

International Nuclear Information System (INIS)

Sun, K. W.; Wang, J. Y.; Ko, T. Y.

2008-01-01

The article reports techniques that we have devised for immobilizing and allocating a single nanodiamond on the electron beam (E-beam) lithography patterned semiconductor substrate. By combining the E-beam patterned smart substrate with the high throughput of a confocal microscope, we are able to overcome the limitation of the spatial resolution of optical techniques (∼1 μm) to obtain the data on individual nano-object with a size range between 100 and 35 nm. We have observed a broad photoluminescence centered at about 700 nm from a single nanodiamond which is due to the defects, vacancies in the nanodiamonds, and the disordered carbon layer covered on the nanodiamond surface. We also observe red-shift in energy and broadening in linewidth of the sp 3 bonding Raman peak when the size of the single nanodiamond is reduced due to the phonon-confinement effects.

Shifts of growing-season precipitation peaks decrease soil respiration in a semiarid grassland.

Science.gov (United States)

Ru, Jingyi; Zhou, Yaqiong; Hui, Dafeng; Zheng, Mengmei; Wan, Shiqiang

2018-03-01

Changing precipitation regimes could have profound influences on carbon (C) cycle in the biosphere. However, how soil C release from terrestrial ecosystems responds to changing seasonal distribution of precipitation remains unclear. A field experiment was conducted for 4 years (2013-2016) to examine the effects of altered precipitation distributions in the growing season on soil respiration in a temperate steppe in the Mongolian Plateau. Over the 4 years, both advanced and delayed precipitation peaks suppressed soil respiration, and the reductions mainly occurred in August. The decreased soil respiration could be primarily attributable to water stress and subsequently limited plant growth (community cover and belowground net primary productivity) and soil microbial activities in the middle growing season, suggesting that precipitation amount in the middle growing season is more important than that in the early, late, or whole growing seasons in regulating soil C release in grasslands. The observations of the additive effects of advanced and delayed precipitation peaks indicate semiarid grasslands will release less C through soil respiratory processes under the projected seasonal redistribution of precipitation in the future. Our findings highlight the potential role of intra-annual redistribution of precipitation in regulating ecosystem C cycling in arid and semiarid regions. © 2017 John Wiley & Sons Ltd.

Does team lifting increase the variability in peak lumbar compression in ironworkers?

Science.gov (United States)

Faber, Gert; Visser, Steven; van der Molen, Henk F; Kuijer, P Paul F M; Hoozemans, Marco J M; Van Dieën, Jaap H; Frings-Dresen, Monique H W

2012-01-01

Ironworkers frequently perform heavy lifting tasks in teams of two or four workers. Team lifting could potentially lead to a higher variation in peak lumbar compression forces than lifts performed by one worker, resulting in higher maximal peak lumbar compression forces. This study compared single-worker lifts (25-kg, iron bar) to two-worker lifts (50-kg, two iron bars) and to four-worker lifts (100-kg, iron lattice). Inverse dynamics was used to calculate peak lumbar compression forces. To assess the variability in peak lumbar loading, all three lifting tasks were performed six times. Results showed that the variability in peak lumbar loading was somewhat higher in the team lifts compared to the single-worker lifts. However, despite this increased variability, team lifts did not result in larger maximum peak lumbar compression forces. Therefore, it was concluded that, from a biomechanical point of view, team lifting does not result in an additional risk for low back complaints in ironworkers.

Probabilistic peak detection for first-order chromatographic data.

Science.gov (United States)

Lopatka, M; Vivó-Truyols, G; Sjerps, M J

2014-03-19

We present a novel algorithm for probabilistic peak detection in first-order chromatographic data. Unlike conventional methods that deliver a binary answer pertaining to the expected presence or absence of a chromatographic peak, our method calculates the probability of a point being affected by such a peak. The algorithm makes use of chromatographic information (i.e. the expected width of a single peak and the standard deviation of baseline noise). As prior information of the existence of a peak in a chromatographic run, we make use of the statistical overlap theory. We formulate an exhaustive set of mutually exclusive hypotheses concerning presence or absence of different peak configurations. These models are evaluated by fitting a segment of chromatographic data by least-squares. The evaluation of these competing hypotheses can be performed as a Bayesian inferential task. We outline the potential advantages of adopting this approach for peak detection and provide several examples of both improved performance and increased flexibility afforded by our approach. Copyright © 2014 Elsevier B.V. All rights reserved.

Genetic Spot Optimization for Peak Power Estimation in Large VLSI Circuits

Directory of Open Access Journals (Sweden)

Michael S. Hsiao

2002-01-01

Full Text Available Estimating peak power involves optimization of the circuit's switching function. The switching of a given gate is not only dependent on the output capacitance of the node, but also heavily dependent on the gate delays in the circuit, since multiple switching events can result from uneven circuit delay paths in the circuit. Genetic spot expansion and optimization are proposed in this paper to estimate tight peak power bounds for large sequential circuits. The optimization spot shifts and expands dynamically based on the maximum power potential (MPP of the nodes under optimization. Four genetic spot optimization heuristics are studied for sequential circuits. Experimental results showed an average of 70.7% tighter peak power bounds for large sequential benchmark circuits was achieved in short execution times.

Statistical analysis of the low-temperature dislocation peak of internal friction (Bordoni peak) in nanostructured copper

International Nuclear Information System (INIS)

Vatazhuk, E.N.; Natsik, V.D.

2011-01-01

The temperature-frequency dependence of internal friction in the nanostructured samples of Cu and fibred composite C-32 vol.%Nb with the sizes of structure fragments approx 200 nm is analyzed. Experiments are used as initial information for such analysis. The characteristic for the heavily deformed copper Bordoni peak, located nearby a temperature 90 K, was recorded on temperature dependence of vibration decrement (frequencies 73-350 kHz) in previous experiments. The peak is due to the resonance interaction of sound with the system of thermal activated relaxators, and its width considerably greater in comparison with the width of standard internal friction peak with the single relaxation time. Statistical analysis of the peak is made in terms of assumption that the reason of broadening is random activation energy dispersion of relaxators as a result of intense distortion of copper crystal structure. Good agreement of experimental data and Seeger theory considers thermal activated paired kinks at linear segments of dislocation lines, placed in potential Peierls relief valley, as relaxators of Bordoni peak, was established. It is shown that the registered peak height in experiment correspond to presence at the average one dislocation segment in the interior of crystalline grain with size of 200 nm. Empirical estimates for the critical Peierls stress σp ∼ 2x10 7 Pa and integrated density of the interior grain dislocations ρ d ∼ 10 13 m -2 are made. Nb fibers in the composite Cu-Nb facilitate to formation of nanostructured copper, but do not influence evidently on the Bordoni peak.

Oxygen uptake during peak graded exercise and single-stage fatigue tests of wheelchair propulsion in manual wheelchair users and the able-bodied.

Science.gov (United States)

Keyser, R E; Rodgers, M M; Gardner, E R; Russell, P J

1999-10-01

To determine if a single-stage, submaximal fatigue test on a wheelchair ergometer would result in higher than expected energy expenditure. An experimental survey design contrasting physiologic responses during peak graded exercise tests and fatigue tests. A rehabilitation science laboratory that included a prototypical wheelchair ergometer, open-circuit spirometry system, and heart rate monitor. Nine able-bodied non-wheelchair users (the NWC group: 6 men and 3 women, mean +/- SD age 30 +/- 7yrs) and 15 manual wheelchair users (the WC group: 12 men and 3 women, age 40 +/- 9yrs, time in wheelchair 16 +/- 9yrs). No subject had any disease, medication regimen, or upper body neurologic, orthopedic, or other condition that would limit wheelchair exercise. Peak oxygen uptake (VO2) for graded exercise testing and during fatigue testing, using a power output corresponding to 75% peak aerobic capacity on graded exercise test. In the WC group, VO2 at 6 minutes of fatigue testing was not significantly different from peak VO2. In the NWC group, VO2 was similar to the expected level throughout fatigue testing. Energy expenditure was higher than expected in the WC group but not in the NWC group. Fatigue testing may provide a useful evaluation of cardiorespiratory status in manual wheelchair users.

Optical energy gaps and photoluminescence peaks of BaGa2S4:Er3+ and BaGa2Se4:Er3+ single crystals

International Nuclear Information System (INIS)

Choe, Sung-Hyu; Jin, Moon-Seog; Kim, Wha-Tek

2005-01-01

BaGa 2 S 4 :Er 3+ and BaGa 2 Se 4 :Er 3+ single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the BaGa 2 S 4 :Er 3+ and the BaGa 2 Se 4 :Er 3+ single crystals were found to be 4.045 eV and 3.073 eV, respectively, at 11 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Sharp emission peaks were observed in the photoluminescence spectra of the single crystals and assigned to radiation recombination between split Stark levels of the Er 3+ ion.

Practical use of chemical shift databases for protein solid-state NMR: 2D chemical shift maps and amino-acid assignment with secondary-structure information

International Nuclear Information System (INIS)

Fritzsching, K. J.; Yang, Y.; Schmidt-Rohr, K.; Hong Mei

2013-01-01

We introduce a Python-based program that utilizes the large database of 13 C and 15 N chemical shifts in the Biological Magnetic Resonance Bank to rapidly predict the amino acid type and secondary structure from correlated chemical shifts. The program, called PACSYlite Unified Query (PLUQ), is designed to help assign peaks obtained from 2D 13 C– 13 C, 15 N– 13 C, or 3D 15 N– 13 C– 13 C magic-angle-spinning correlation spectra. We show secondary-structure specific 2D 13 C– 13 C correlation maps of all twenty amino acids, constructed from a chemical shift database of 262,209 residues. The maps reveal interesting conformation-dependent chemical shift distributions and facilitate searching of correlation peaks during amino-acid type assignment. Based on these correlations, PLUQ outputs the most likely amino acid types and the associated secondary structures from inputs of experimental chemical shifts. We test the assignment accuracy using four high-quality protein structures. Based on only the Cα and Cβ chemical shifts, the highest-ranked PLUQ assignments were 40–60 % correct in both the amino-acid type and the secondary structure. For three input chemical shifts (CO–Cα–Cβ or N–Cα–Cβ), the first-ranked assignments were correct for 60 % of the residues, while within the top three predictions, the correct assignments were found for 80 % of the residues. PLUQ and the chemical shift maps are expected to be useful at the first stage of sequential assignment, for combination with automated sequential assignment programs, and for highly disordered proteins for which secondary structure analysis is the main goal of structure determination.

Peak-locking reduction for particle image velocimetry

International Nuclear Information System (INIS)

Michaelis, Dirk; Wieneke, Bernhard; Neal, Douglas R

2016-01-01

A parametric study of the factors contributing to peak-locking, a known bias error source in particle image velocimetry (PIV), is conducted using synthetic data that are processed with a state-of-the-art PIV algorithm. The investigated parameters include: particle image diameter, image interpolation techniques, the effect of asymmetric versus symmetric window deformation, number of passes and the interrogation window size. Some of these parameters are found to have a profound effect on the magnitude of the peak-locking error. The effects for specific PIV cameras are also studied experimentally using a precision turntable to generate a known rotating velocity field. Image time series recorded using this experiment show a linear range of pixel and sub-pixel shifts ranging from 0 to  ±4 pixels. Deviations in the constant vorticity field (ω z ) reveal how peak-locking can be affected systematically both by varying parameters of the detection system such as the focal distance and f -number, and also by varying the settings of the PIV analysis. A new a priori technique for reducing the bias errors associated with peak-locking in PIV is introduced using an optical diffuser to avoid undersampled particle images during the recording of the raw images. This technique is evaluated against other a priori approaches using experimental data and is shown to perform favorably. Finally, a new a posteriori anti peak-locking filter (APLF) is developed and investigated, which shows promising results for both synthetic data and real measurements for very small particle image sizes. (paper)

Influence of photo- and thermal bleaching on pre-irradiation low water peak single mode fibers

Science.gov (United States)

Yin, Jianchong; Wen, Jianxiang; Luo, Wenyun; Xiao, Zhongyin; Chen, Zhenyi; Wang, Tingyun

2011-12-01

Reducing the radiation-induced transmission loss in low water peak single mode fiber (LWP SMF) has been investigated by using photo-bleaching method with 980nm pump light source and using thermal-bleaching method with temperature control system. The results show that the radiation-induced loss of pre-irradiation optical fiber can be reduced effectively with the help of photo-bleaching or thermal-bleaching. Although the effort of photo-bleaching is not as significant as thermal-bleaching, by using photo-bleaching method, the loss of fiber caused by radiation-induced defects can be reduced best up to 49% at 1310nm and 28% at 1550nm in low pre-irradiation condition, the coating of the fiber are not destroyed, and the rehabilitating time is just several hours, while self-annealing usually costs months' time. What's more, the typical high power LASER for photo-bleaching can be 980nm pump Laser Diode, which is very accessible.

Work shifts in Emergency Medicine

Directory of Open Access Journals (Sweden)

Roberto Recupero

2007-06-01

Full Text Available Emergency Medicine is known as a high stress specialty. The adverse effect of constantly rotating shifts is the single most important reason given for premature attrition from the field. In this work problems tied with night shift work will be taken into account and some solutions to reduce the impact of night work on the emergency physicians will be proposed.

A neutron polarisation analysis study of the 'central' peak in single-crystal praseodymium

International Nuclear Information System (INIS)

Burke, S.K.; Stirling, W.G.; McEwen, K.A.; Salford Univ.

1981-01-01

The technique of neutron polarisation analysis has been used to examine the broad 'central' peak in paramagnetic praseodymium. Measurements over the temperature range 1.2-25 K show that these peaks, observed at reciprocal space positions (Q 1 , 0, 2m + 1) with Q 1 = 0.11 tau 100 , are entirely magnetic in character. The relationship between these short-range magnetic correlations and the long-range antiferromagnetic ordering process is discussed. (author)

Gain-assisted control of the Goos-Haenchen shift

Energy Technology Data Exchange (ETDEWEB)

Ziauddin,; Qamar, Sajid [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

2011-11-15

A gain-assisted model is considered to study the Goos-Haenchen (GH) shift behavior in the reflected and transmitted light. In this model, a probe light is incident on a cavity containing three-level dilute gaseous atomic medium. The atom-field interaction follows two-photon Raman transitions, and the dielectric susceptibility of the medium exhibits dispersion and gain properties [L. J. Wang, A. Kuzmich, and A. Dogariu, Nature (London) 406, 227 (2000)]. Under appropriate conditions, two gain peaks are observed with anomalous dispersion between the peaks, whereas normal dispersion can be observed at and around the gain maxima. The manipulation of the detuning associated with the probe light field which interacts with the intracavity medium during its propagation through the cavity can lead to a control over negative and positive GH shift in the reflected and transmitted light beam via the anomalous and normal dispersion of the medium.

Fully differential cross sections for the single ionization of helium by fast ions: Classical model calculations

Science.gov (United States)

Sarkadi, L.

2018-04-01

Fully differential cross sections (FDCSs) have been calculated for the single ionization of helium by 1- and 3-MeV proton and 100-MeV/u C6 + ion impact using the classical trajectory Monte Carlo (CTMC) method in the nonrelativistic, three-body approximation. The calculations were made employing a Wigner-type model in which the quantum-mechanical position distribution of the electron is approximated by a weighted integral of the microcanonical distribution over a range of the binding energy of the electron. In the scattering plane, the model satisfactorily reproduces the observed shape of the binary peak. In the region of the peak the calculated FDCSs agree well with the results of continuum-distorted-wave calculations for all the investigated collisions. For 1-MeV proton impact the experimentally observed shift of the binary peak with respect to the first Born approximation is compared with the shifts obtained by different higher-order quantum-mechanical theories and the present CTMC method. The best result was achieved by CTMC, but still a large part of the shift remained unexplained. Furthermore, it was found that the classical theory failed to reproduce the shape of the recoil peak observed in the experiments, it predicts a much narrower peak. This indicates that the formation of the recoil peak is dominated by quantum-mechanical effects. For 100-MeV/u C6 + ion impact the present CTMC calculations confirmed the existence of the "double-peak" structure of the angular distribution of the electron in the plane perpendicular to the momentum transfer, in accordance with the observation, the prediction of an incoherent semiclassical model, and previous CTMC results. This finding together with wave-packet calculations suggests that the "C6 + puzzle" may be solved by considering the loss of the projectile coherence. Experiments to be conducted using ion beams of anisotropic coherence are proposed for a more differential investigation of the ionization dynamics.

Layout of NALM fiber laser with adjustable peak power of generated pulses.

Science.gov (United States)

Smirnov, Sergey; Kobtsev, Sergey; Ivanenko, Alexey; Kokhanovskiy, Alexey; Kemmer, Anna; Gervaziev, Mikhail

2017-05-01

The Letter proposes a new layout of a passively mode-locked fiber laser based on a nonlinear amplifying loop mirror (NALM) with two stretches of active fiber and two independently controlled pump modules. In contrast with conventional NALM configurations using a single piece of active fiber that yields virtually constant peak power, the proposed novel laser features larger than a factor of 2 adjustment range of peak power of generated pulses. The proposed layout also provides independent adjustment of duration and peak power of generated pulses as well as power-independent control of generated pulse spectral width impossible in NALM lasers with a single piece of active fiber.

Practical use of chemical shift databases for protein solid-state NMR: 2D chemical shift maps and amino-acid assignment with secondary-structure information

Energy Technology Data Exchange (ETDEWEB)

Fritzsching, K. J.; Yang, Y.; Schmidt-Rohr, K.; Hong Mei, E-mail: mhong@iastate.edu [Iowa State University, Department of Chemistry (United States)

2013-06-15

We introduce a Python-based program that utilizes the large database of {sup 13}C and {sup 15}N chemical shifts in the Biological Magnetic Resonance Bank to rapidly predict the amino acid type and secondary structure from correlated chemical shifts. The program, called PACSYlite Unified Query (PLUQ), is designed to help assign peaks obtained from 2D {sup 13}C-{sup 13}C, {sup 15}N-{sup 13}C, or 3D {sup 15}N-{sup 13}C-{sup 13}C magic-angle-spinning correlation spectra. We show secondary-structure specific 2D {sup 13}C-{sup 13}C correlation maps of all twenty amino acids, constructed from a chemical shift database of 262,209 residues. The maps reveal interesting conformation-dependent chemical shift distributions and facilitate searching of correlation peaks during amino-acid type assignment. Based on these correlations, PLUQ outputs the most likely amino acid types and the associated secondary structures from inputs of experimental chemical shifts. We test the assignment accuracy using four high-quality protein structures. Based on only the C{alpha} and C{beta} chemical shifts, the highest-ranked PLUQ assignments were 40-60 % correct in both the amino-acid type and the secondary structure. For three input chemical shifts (CO-C{alpha}-C{beta} or N-C{alpha}-C{beta}), the first-ranked assignments were correct for 60 % of the residues, while within the top three predictions, the correct assignments were found for 80 % of the residues. PLUQ and the chemical shift maps are expected to be useful at the first stage of sequential assignment, for combination with automated sequential assignment programs, and for highly disordered proteins for which secondary structure analysis is the main goal of structure determination.

Automation of peak-tracking analysis of stepwise perturbed NMR spectra

Energy Technology Data Exchange (ETDEWEB)

Banelli, Tommaso; Vuano, Marco [Università di Udine, Dipartimento di Area Medica (Italy); Fogolari, Federico [INBB (Italy); Fusiello, Andrea [Università di Udine, Dipartimento Politecnico di Ingegneria e Architettura (Italy); Esposito, Gennaro [INBB (Italy); Corazza, Alessandra, E-mail: alessandra.corazza@uniud.it [Università di Udine, Dipartimento di Area Medica (Italy)

2017-02-15

We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TinT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TinT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TinT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial.

Optical properties of graphene nanoribbons encapsulated in single-walled carbon nanotubes.

Science.gov (United States)

Chernov, Alexander I; Fedotov, Pavel V; Talyzin, Alexandr V; Suarez Lopez, Inma; Anoshkin, Ilya V; Nasibulin, Albert G; Kauppinen, Esko I; Obraztsova, Elena D

2013-07-23

We report the photoluminescence (PL) from graphene nanoribbons (GNRs) encapsulated in single-walled carbon nanotubes (SWCNTs). New PL spectral features originating from GNRs have been detected in the visible spectral range. PL peaks from GNRs have resonant character, and their positions depend on the ribbon geometrical structure in accordance with the theoretical predictions. GNRs were synthesized using confined polymerization and fusion of coronene molecules. GNR@SWCNTs material demonstrates a bright photoluminescence both in infrared (IR) and visible regions. The photoluminescence excitation mapping in the near-IR spectral range has revealed the geometry-dependent shifts of the SWCNT peaks (up to 11 meV in excitation and emission) after the process of polymerization of coronene molecules inside the nanotubes. This behavior has been attributed to the strain of SWCNTs induced by insertion of the coronene molecules.

Absolute determination of zero-energy phase shifts for multiparticle single-channel scattering: Generalized Levinson theorem

International Nuclear Information System (INIS)

Rosenberg, L.; Spruch, L.

1996-01-01

Levinson close-quote s theorem relates the zero-energy phase shift δ for potential scattering in a given partial wave l, by a spherically symmetric potential that falls off sufficiently rapidly, to the number of bound states of that l supported by the potential. An extension of this theorem is presented that applies to single-channel scattering by a compound system initially in its ground state. As suggested by Swan [Proc. R. Soc. London Ser. A 228, 10 (1955)], the extended theorem differs from that derived for potential scattering; even in the absence of composite bound states δ may differ from zero as a consequence of the Pauli principle. The derivation given here is based on the introduction of a continuous auxiliary open-quote open-quote length phase close-quote close-quote η, defined modulo π for l=0 by expressing the scattering length as A=acotη, where a is a characteristic length of the target. Application of the minimum principle for the scattering length determines the branch of the cotangent curve on which η lies and, by relating η to δ, an absolute determination of δ is made. The theorem is applicable, in principle, to single-channel scattering in any partial wave for e ± -atom and nucleon-nucleus systems. In addition to a knowledge of the number of composite bound states, information (which can be rather incomplete) concerning the structure of the target ground-state wave function is required for an explicit, absolute, determination of the phase shift δ. As for Levinson close-quote s original theorem for potential scattering, no additional information concerning the scattering wave function or scattering dynamics is required. copyright 1996 The American Physical Society

KiDS-450: cosmological constraints from weak-lensing peak statistics - II: Inference from shear peaks using N-body simulations

Science.gov (United States)

Martinet, Nicolas; Schneider, Peter; Hildebrandt, Hendrik; Shan, HuanYuan; Asgari, Marika; Dietrich, Jörg P.; Harnois-Déraps, Joachim; Erben, Thomas; Grado, Aniello; Heymans, Catherine; Hoekstra, Henk; Klaes, Dominik; Kuijken, Konrad; Merten, Julian; Nakajima, Reiko

2018-02-01

We study the statistics of peaks in a weak-lensing reconstructed mass map of the first 450 deg2 of the Kilo Degree Survey (KiDS-450). The map is computed with aperture masses directly applied to the shear field with an NFW-like compensated filter. We compare the peak statistics in the observations with that of simulations for various cosmologies to constrain the cosmological parameter S_8 = σ _8 √{Ω _m/0.3}, which probes the (Ωm, σ8) plane perpendicularly to its main degeneracy. We estimate S8 = 0.750 ± 0.059, using peaks in the signal-to-noise range 0 ≤ S/N ≤ 4, and accounting for various systematics, such as multiplicative shear bias, mean redshift bias, baryon feedback, intrinsic alignment, and shear-position coupling. These constraints are ˜ 25 per cent tighter than the constraints from the high significance peaks alone (3 ≤ S/N ≤ 4) which typically trace single-massive haloes. This demonstrates the gain of information from low-S/N peaks. However, we find that including S/N KiDS-450. Combining shear peaks with non-tomographic measurements of the shear two-point correlation functions yields a ˜20 per cent improvement in the uncertainty on S8 compared to the shear two-point correlation functions alone, highlighting the great potential of peaks as a cosmological probe.

Single-longitudinal-mode BEFL incorporating a Bragg grating written in EDF

Science.gov (United States)

Gao, Ya; Sun, Junqiang; Chen, Guodong; Xie, Heng

2015-06-01

A stable and tunable single-longitudinal-mode (SLM) Brillouin/Erbium fiber laser (BEFL) with narrow linewidth is proposed and experimentally demonstrated. A uniform Bragg grating written in a segment of unpumped Erbium-doped fiber (EDF) is incorporated as an auto-tracking filter to achieve SLM operation. A length of 5 m pumped EDF is used to provide both Brillouin and linear gain in the cavity. The linewidth is measured to be 18 kHz and the lasing peak power fluctuation and wavelength shift are monitored less than 0.027 dB and 2 pm respectively.

Combined chemical shift changes and amino acid specific chemical shift mapping of protein-protein interactions

Energy Technology Data Exchange (ETDEWEB)

Schumann, Frank H.; Riepl, Hubert [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany); Maurer, Till [Boehringer Ingelheim Pharma GmbH and Co. KG, Analytical Sciences Department (Germany); Gronwald, Wolfram [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany); Neidig, Klaus-Peter [Bruker BioSpin GmbH, Software Department (Germany); Kalbitzer, Hans Robert [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany)], E-mail: hans-robert.kalbitzer@biologie.uni-regensburg.de

2007-12-15

Protein-protein interactions are often studied by chemical shift mapping using solution NMR spectroscopy. When heteronuclear data are available the interaction interface is usually predicted by combining the chemical shift changes of different nuclei to a single quantity, the combined chemical shift perturbation {delta}{delta}{sub comb}. In this paper different procedures (published and non-published) to calculate {delta}{delta}{sub comb} are examined that include a variety of different functional forms and weighting factors for each nucleus. The predictive power of all shift mapping methods depends on the magnitude of the overlap of the chemical shift distributions of interacting and non-interacting residues and the cut-off criterion used. In general, the quality of the prediction on the basis of chemical shift changes alone is rather unsatisfactory but the combination of chemical shift changes on the basis of the Hamming or the Euclidian distance can improve the result. The corrected standard deviation to zero of the combined chemical shift changes can provide a reasonable cut-off criterion. As we show combined chemical shifts can also be applied for a more reliable quantitative evaluation of titration data.

Quenching and blue shift of UV emission intensity of hydrothermally grown ZnO:Mn nanorods

Energy Technology Data Exchange (ETDEWEB)

Vinod, R. [Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Junaid Bushiri, M., E-mail: junaidbushiri@gmail.com [Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Achary, Sreekumar Rajappan; Muñoz-Sanjosé, Vicente [Departamento de FisicaAplicada y Electromagnetismo, Universitat de Valencia, c/Dr. Moliner 50, Burjassot, Valencia 46100 (Spain)

2015-01-15

Highlights: • Single crystalline ZnO:Mn nanorods. • Reduced optical active defects. • Quenching and blue shift of UV emission. - Abstract: ZnO:Mn alloyed nanorods (Mn nominal concentration – 3–5 wt%) were synthesized by using hydrothermal process at an optimized growth temperature of 200 °C and a growth time of 3 h. The XRD, SEM and Raman, FTIR investigations reveal that ZnO:Mn (Mn – 3–5 wt%) retained hexagonal wurtzite crystal structure with nanorod morphology. The HRTEM and SAED analysis confirm the single crystalline nature of hydrothermally grown ZnO and ZnO:Mn (5 wt%) nanorods. The ZnO:Mn nanorods (Mn – 0–5 wt%) displayed optical band gap in the range 3.23–3.28 eV. The blue shift of UV emission peak (PL) from 393 (ZnO) to 386 nm and quenching of photoluminescence emission in ZnO:Mn is due to the Mn incorporation in ZnO lattice. Relative increase in intensity of Raman band at 660 cm{sup −1} with nominal doping of Mn 3–5 wt% in ZnO indicate that defects are introduced in ZnO:Mn system as a result of doping that leads to the quenching of photoluminescence emission at 393 nm.

An Auto Tuning Substation Peak Shaving Controller for Congestion Management Using Flexible Demand

DEFF Research Database (Denmark)

Sossan, Fabrizio; Marinelli, Mattia

2013-01-01

A closed loop substation peak shaving/congestion management controller for radial distribution networks is presented. The controller it uses an individual control signal in order to shift the consumption of a population of demand side resources, DSRs. The controller auto tunes its parameters on...

SU-F-J-208: Prompt Gamma Imaging-Based Prediction of Bragg Peak Position for Realistic Treatment Error Scenarios

Energy Technology Data Exchange (ETDEWEB)

Xing, Y; Macq, B; Bondar, L [Universite catholique de Louvain, Louvain-la-Neuve (Belgium); Janssens, G [IBA, Louvain-la-Neuve (Belgium)

2016-06-15

Purpose: To quantify the accuracy in predicting the Bragg peak position using simulated in-room measurements of prompt gamma (PG) emissions for realistic treatment error scenarios that combine several sources of errors. Methods: Prompt gamma measurements by a knife-edge slit camera were simulated using an experimentally validated analytical simulation tool. Simulations were performed, for 143 treatment error scenarios, on an anthropomorphic phantom and a pencil beam scanning plan for nasal cavity. Three types of errors were considered: translation along each axis, rotation around each axis, and CT-calibration errors with magnitude ranging respectively, between −3 and 3 mm, −5 and 5 degrees, and between −5 and +5%. We investigated the correlation between the Bragg peak (BP) shift and the horizontal shift of PG profiles. The shifts were calculated between the planned (reference) position and the position by the error scenario. The prediction error for one spot was calculated as the absolute difference between the PG profile shift and the BP shift. Results: The PG shift was significantly and strongly correlated with the BP shift for 92% of the cases (p<0.0001, Pearson correlation coefficient R>0.8). Moderate but significant correlations were obtained for all cases that considered only CT-calibration errors and for 1 case that combined translation and CT-errors (p<0.0001, R ranged between 0.61 and 0.8). The average prediction errors for the simulated scenarios ranged between 0.08±0.07 and 1.67±1.3 mm (grand mean 0.66±0.76 mm). The prediction error was moderately correlated with the value of the BP shift (p=0, R=0.64). For the simulated scenarios the average BP shift ranged between −8±6.5 mm and 3±1.1 mm. Scenarios that considered combinations of the largest treatment errors were associated with large BP shifts. Conclusion: Simulations of in-room measurements demonstrate that prompt gamma profiles provide reliable estimation of the Bragg peak position for

Fuzzy Determination of Target Shifting Time and Torque Control of Shifting Phase for Dry Dual Clutch Transmission

Directory of Open Access Journals (Sweden)

Zhiguo Zhao

2014-01-01

Full Text Available Based on the independently developed five-speed dry dual clutch transmission (DDCT, the paper proposes the torque coordinating control strategy between engine and two clutches, which obtains engine speed and clutch transferred torque in the shifting process, adequately reflecting the driver intention and improving the shifting quality. Five-degree-of-freedom (DOF shifting dynamics model of DDCT with single intermediate shaft is firstly established according to its physical characteristics. Then the quantitative control objectives of the shifting process are presented. The fuzzy decision of shifting time and the model-based torque coordinating control strategy are proposed and also verified by simulating under different driving intentions in up-/downshifting processes with the DCT model established on the MATLAB/Simulink. Simulation results validate that the shifting control algorithm proposed in this paper can not only meet the shifting quality requirements, but also adapt to the various shifting intentions, having a strong robustness.

The Peak Pairs algorithm for strain mapping from HRTEM images

Energy Technology Data Exchange (ETDEWEB)

Galindo, Pedro L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)], E-mail: pedro.galindo@uca.es; Kret, Slawomir [Institute of Physics, PAS, AL. Lotnikow 32/46, 02-668 Warsaw (Poland); Sanchez, Ana M. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Laval, Jean-Yves [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, Paris (France); Yanez, Andres; Pizarro, Joaquin; Guerrero, Elisa [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Ben, Teresa; Molina, Sergio I. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)

2007-11-15

Strain mapping is defined as a numerical image-processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. Algorithms to map elastic strains from high-resolution transmission electron microscopy (HRTEM) images may be classified into two categories: those based on the detection of peaks of intensity in real space and the Geometric Phase approach, calculated in Fourier space. In this paper, we discuss both categories and propose an alternative real space algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in an affine transformed space dependent on the reference area. In spite of the fact that it is a real space approach, the Peak Pairs algorithm exhibits good behaviour at heavily distorted defect cores, e.g. interfaces and dislocations. Quantitative results are reported from experiments to determine local strain in different types of semiconductor heterostructures.

Analysis of reflection-peak wavelengths of sampled fiber Bragg gratings with large chirp.

Science.gov (United States)

Zou, Xihua; Pan, Wei; Luo, Bin

2008-09-10

The reflection-peak wavelengths (RPWs) in the spectra of sampled fiber Bragg gratings with large chirp (SFBGs-LC) are theoretically investigated. Such RPWs are divided into two parts, the RPWs of equivalent uniform SFBGs (U-SFBGs) and the wavelength shift caused by the large chirp in the grating period (CGP). We propose a quasi-equivalent transform to deal with the CGP. That is, the CGP is transferred into quasi-equivalent phase shifts to directly derive the Fourier transform of the refractive index modulation. Then, in the case of both the direct and the inverse Talbot effect, the wavelength shift is obtained from the Fourier transform. Finally, the RPWs of SFBGs-LC can be achieved by combining the wavelength shift and the RPWs of equivalent U-SFBGs. Several simulations are shown to numerically confirm these predicted RPWs of SFBGs-LC.

Characteristics of InAs/InGaAs/GaAs QDs on GeOI substrates with single-peak 1.3 µm room-temperature emission

International Nuclear Information System (INIS)

Liang, Y Y; Yoon, S F; Loke, W K; Ngo, C Y; Fitzgerald, E A

2012-01-01

GaAs-based quantum dot (QD) systems, especially InAs/InGaAs/GaAs QDs, have demonstrated superior device performances as compared with higher dimensional systems. However, to realize high-speed optical interconnects for Si-based electronics, one will need to grow the QDs on Si substrates. While it is promising to integrate the InAs/InGaAs/GaAs QDs on Si with the use of germanium-on-insulator-on-silicon (GeOI) substrates, reported results exhibit bimodal QD sizes and double emission peaks, i.e. unsatisfactory for realistic applications. In this paper, we showed that with an optimized GaAs buffer, single-peak 1.33 µm room-temperature emission can be obtained from InAs/InGaAs/GaAs QDs on GeOI substrates. (paper)

Variation of the binary encounter peak energy as a function of projectile atomic number

International Nuclear Information System (INIS)

Sanders, J.M.

1994-01-01

The energy of the binary encounter peak, in spectra of electrons emitted at 0 degrees with respect to the projectile beam direction, has been studied to investigate its dependence on the atomic number of the projectile ion. The projectiles all had the same squared velocity of 0.6 MeV/u, and all had the same charge q=7. The Z of the projectiles ranged from 8 to 35, and the target was H 2 . The Energy E BEP of the binary encounter peak and also the energy t of the cusp formed by electron loss or electron capture to the projectile continuum (ELC or ECC) were obtained from fits to the spectra. Considerable care was required in fitting the cusp in order to properly ascertain the cusp energy. The energy shift ΔE, defined as the difference between 4t and E BEP , was obtained for each projectile. It is found that the energy shift decreases as the projectile Z increases. This trend is the opposite of that seen for projectile charge where the shift increases as q increases. Such a trend is not well described by the simple elastic scattering model of binary encounter electron production

Phase-Shifted Eccentric Core Fiber Bragg Grating Fabricated by Electric Arc Discharge for Directional Bending Measurement.

Science.gov (United States)

Ouyang, Yang; Liu, Jianxia; Xu, Xiaofeng; Zhao, Yujia; Zhou, Ai

2018-04-11

A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG) fabricated by electric arc discharge (EAD) is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m -1 and -51.5 pm/m -1 , respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively.

MERGERS IN DOUBLE-PEAKED [O III] ACTIVE GALACTIC NUCLEI

International Nuclear Information System (INIS)

Fu Hai; Djorgovski, S. G.; Myers, Adam D.; Yan Lin

2011-01-01

As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than 10 kpc. Such a system may show two sets of narrow emission lines in a single spectrum owing to the orbital motion of the binary. We have obtained high-resolution near-infrared images of 50 double-peaked [O III]λ5007 AGNs with the Keck II laser guide star adaptive optics system. The Sloan Digital Sky Survey sample is compiled from the literature and consists of 17 type-1 AGNs between 0.18 BH -σ * relation because of overestimated stellar velocity dispersions, illustrating the importance of removing mergers from the samples defining the M BH -σ * relations. Finally, we find that the emission-line properties are indistinguishable for spatially resolved and unresolved sources, emphasizing that scenarios involving a single AGN can produce the same double-peaked line profiles and they account for at least 70% of the double-peaked [O III] AGNs.

Relaxation peak near 200 K in NiTi alloy

Science.gov (United States)

Zhu, J. S.; Schaller, R.; Benoit, W.

1989-10-01

Internal friction (IF), frequency ( f), electrical resistance ( R) and zero point movement of the torsion pendulum (ɛ) have been measured in near equi-atomic NiTi alloy in order to clarify the mechanism for the relaxation peak near 200 K. The height of the relaxation peak decreases successively with thermal cycling and settles down to a lower stable value in running 15 cycles. However, the electrical resistance of the sample shows a variation in contrast with the internal friction. Both of them will return to the initial state after a single annealing at 773 K for 1 h. The probable mechanism of this relaxation peak was discussed.

Advancements of ultra-high peak power laser diode arrays

Science.gov (United States)

Crawford, D.; Thiagarajan, P.; Goings, J.; Caliva, B.; Smith, S.; Walker, R.

2018-02-01

Enhancements of laser diode epitaxy in conjunction with process and packaging improvements have led to the availability of 1cm bars capable of over 500W peak power at near-infrared wavelengths (770nm to 1100nm). Advances in cooler design allow for multi-bar stacks with bar-to-bar pitches as low as 350μm and a scalable package architecture enabled a single diode assembly with total peak powers of over 1MegaWatt of peak power. With the addition of micro-optics, overall array brightness greater than 10kW/cm2 was achieved. Performance metrics of barbased diode lasers specifically engineered for high peak power and high brightness at wavelengths and pulse conditions commonly used to pump a variety of fiber and solid-state materials are presented.

Giant Lamb shift in photonic crystals

International Nuclear Information System (INIS)

Wang Xuehua; Kivshar, Yuri S.; Gu Benyuan

2004-01-01

We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases

Hyperfine structure and isotope shift analysis of singly ionized titanium

Science.gov (United States)

Bouazza, Safa

2013-04-01

The even-parity low configuration system of Ti II has been considered on the basis of the experimental data found in the literature, and its fine structure has been reanalyzed by simultaneous parameterization of one- and two-body interactions for the model space (3d + 4s)3. Furthermore, the main one-electron hyperfine structure parameters for these configurations have been evaluated. For instance, for 3d24s1, a_{3{\\rm{d}}}^{01} = - {\\rm{63}}.{\\rm{2}}\\left( {{\\rm{3}}.{\\rm{1}}} \\right)\\,{\\rm{MHz}} and a_{4{\\rm{s}}}^{10} = - {\\rm{984}}.{\\rm{1}}\\left( {{\\rm{7}}.{\\rm{1}}} \\right)\\,{\\rm{MHz}} . Field shifts (FS) and specific mass shifts (SMS) of the main Ti II configurations are deduced by means of ab initio estimates combined with a small quantity of experimental isotope shift data available in the literature: FS(3d3) = -63.3 MHz, FS(3d24p1) = -49.7 MHz, FS(3d14s2) = 98.2 MHz, FS(4s24P1) = 163.4 MHz and SMS(3d3) = 1453.3 MHz, SMS(3d14s2) = -2179.7 MHz, …, referred to 3d24s1 for the pair Ti46-Ti48.

Real - time Optimization of Distributed Energy Storage System Operation Strategy Based on Peak Load Shifting

Science.gov (United States)

Wang, Qian; Lu, Guangqi; Li, Xiaoyu; Zhang, Yichi; Yun, Zejian; Bian, Di

2018-01-01

To take advantage of the energy storage system (ESS) sufficiently, the factors that the service life of the distributed energy storage system (DESS) and the load should be considered when establishing optimization model. To reduce the complexity of the load shifting of DESS in the solution procedure, the loss coefficient and the equal capacity ratio distribution principle were adopted in this paper. Firstly, the model was established considering the constraint conditions of the cycles, depth, power of the charge-discharge of the ESS, the typical daily load curves, as well. Then, dynamic programming method was used to real-time solve the model in which the difference of power Δs, the real-time revised energy storage capacity Sk and the permission error of depth of charge-discharge were introduced to optimize the solution process. The simulation results show that the optimized results was achieved when the load shifting in the load variance was not considered which means the charge-discharge of the energy storage system was not executed. In the meantime, the service life of the ESS would increase.

Tidal and near-inertial peak variations around the diurnal critical latitude

Science.gov (United States)

van Haren, Hans

2005-12-01

Spectra from historic long-term open-ocean moored current meter data between latitudes 0° shift of the peak frequency to 0.97 +/- 0.01f, or a poleward spreading of enhanced energy. This contrasts with more common blue-shift. The enhancement may be the result of sub-harmonic instability, as supported by sparse significant bicoherence at half-D2, although i) systematic enhancement of diurnal tidal frequencies, notably M1, was not observed, ii) the latitudes of low D2-energy and high f-energy do not coincide. This may be due to a mix of coupled and independent waves, whilst the poleward trapping of sub-f energy suggests non-traditional effects.

Combining automated peak tracking in SAR by NMR with structure-based backbone assignment from 15N-NOESY

KAUST Repository

Jang, Richard; Gao, Xin; Li, Ming

2012-01-01

Background: Chemical shift mapping is an important technique in NMR-based drug screening for identifying the atoms of a target protein that potentially bind to a drug molecule upon the molecule's introduction in increasing concentrations. The goal is to obtain a mapping of peaks with known residue assignment from the reference spectrum of the unbound protein to peaks with unknown assignment in the target spectrum of the bound protein. Although a series of perturbed spectra help to trace a path from reference peaks to target peaks, a one-to-one mapping generally is not possible, especially for large proteins, due to errors, such as noise peaks, missing peaks, missing but then reappearing, overlapped, and new peaks not associated with any peaks in the reference. Due to these difficulties, the mapping is typically done manually or semi-automatically, which is not efficient for high-throughput drug screening.Results: We present PeakWalker, a novel peak walking algorithm for fast-exchange systems that models the errors explicitly and performs many-to-one mapping. On the proteins: hBclXL, UbcH5B, and histone H1, it achieves an average accuracy of over 95% with less than 1.5 residues predicted per target peak. Given these mappings as input, we present PeakAssigner, a novel combined structure-based backbone resonance and NOE assignment algorithm that uses just 15N-NOESY, while avoiding TOCSY experiments and 13C-labeling, to resolve the ambiguities for a one-to-one mapping. On the three proteins, it achieves an average accuracy of 94% or better.Conclusions: Our mathematical programming approach for modeling chemical shift mapping as a graph problem, while modeling the errors directly, is potentially a time- and cost-effective first step for high-throughput drug screening based on limited NMR data and homologous 3D structures. 2012 Jang et al.; licensee BioMed Central Ltd.

Combining automated peak tracking in SAR by NMR with structure-based backbone assignment from 15N-NOESY

KAUST Repository

Jang, Richard

2012-03-21

Background: Chemical shift mapping is an important technique in NMR-based drug screening for identifying the atoms of a target protein that potentially bind to a drug molecule upon the molecule\\'s introduction in increasing concentrations. The goal is to obtain a mapping of peaks with known residue assignment from the reference spectrum of the unbound protein to peaks with unknown assignment in the target spectrum of the bound protein. Although a series of perturbed spectra help to trace a path from reference peaks to target peaks, a one-to-one mapping generally is not possible, especially for large proteins, due to errors, such as noise peaks, missing peaks, missing but then reappearing, overlapped, and new peaks not associated with any peaks in the reference. Due to these difficulties, the mapping is typically done manually or semi-automatically, which is not efficient for high-throughput drug screening.Results: We present PeakWalker, a novel peak walking algorithm for fast-exchange systems that models the errors explicitly and performs many-to-one mapping. On the proteins: hBclXL, UbcH5B, and histone H1, it achieves an average accuracy of over 95% with less than 1.5 residues predicted per target peak. Given these mappings as input, we present PeakAssigner, a novel combined structure-based backbone resonance and NOE assignment algorithm that uses just 15N-NOESY, while avoiding TOCSY experiments and 13C-labeling, to resolve the ambiguities for a one-to-one mapping. On the three proteins, it achieves an average accuracy of 94% or better.Conclusions: Our mathematical programming approach for modeling chemical shift mapping as a graph problem, while modeling the errors directly, is potentially a time- and cost-effective first step for high-throughput drug screening based on limited NMR data and homologous 3D structures. 2012 Jang et al.; licensee BioMed Central Ltd.

THE ROLE OF FISSION IN NEUTRON STAR MERGERS AND ITS IMPACT ON THE r-PROCESS PEAKS

International Nuclear Information System (INIS)

Eichler, M.; Panov, I.; Rauscher, T.; Thielemann, F.-K.; Arcones, A.; Langanke, K.; Martinez-Pinedo, G.; Kelic, A.; Korobkin, O.; Rosswog, S.; Marketin, T.; Winteler, C.; Zinner, N. T.

2015-01-01

Comparing observational abundance features with nucleosynthesis predictions of stellar evolution or explosion simulations, we can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. We test the abundance features of r-process nucleosynthesis calculations for the dynamical ejecta of neutron star merger simulations based on three different nuclear mass models: The Finite Range Droplet Model, the (quenched version of the) Extended Thomas Fermi Model with Strutinsky Integral, and the Hartree–Fock–Bogoliubov mass model. We make use of corresponding fission barrier heights and compare the impact of four different fission fragment distribution models on the final r-process abundance distribution. In particular, we explore the abundance distribution in the second r-process peak and the rare-earth sub-peak as a function of mass models and fission fragment distributions, as well as the origin of a shift in the third r-process peak position. The latter has been noticed in a number of merger nucleosynthesis predictions. We show that the shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)–(γ,n) equilibrium is no longer maintained. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of β-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well

THE ROLE OF FISSION IN NEUTRON STAR MERGERS AND ITS IMPACT ON THE r-PROCESS PEAKS

Energy Technology Data Exchange (ETDEWEB)

Eichler, M.; Panov, I.; Rauscher, T.; Thielemann, F.-K. [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Arcones, A.; Langanke, K.; Martinez-Pinedo, G. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 2, D-64289 Darmstadt (Germany); Kelic, A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Korobkin, O.; Rosswog, S. [The Oskar Klein Centre, Department of Astronomy, AlbaNova, Stockholm University, SE-106 91 Stockholm (Sweden); Marketin, T. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Winteler, C. [Institut Energie am Bau, Fachhochschule Nordwestschweiz, St. Jakobs-Strasse 84, 4132 Muttenz (Switzerland); Zinner, N. T., E-mail: marius.eichler@unibas.ch [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, bygn. 1520, DK-8000 Aarhus C (Denmark)

2015-07-20

Comparing observational abundance features with nucleosynthesis predictions of stellar evolution or explosion simulations, we can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. We test the abundance features of r-process nucleosynthesis calculations for the dynamical ejecta of neutron star merger simulations based on three different nuclear mass models: The Finite Range Droplet Model, the (quenched version of the) Extended Thomas Fermi Model with Strutinsky Integral, and the Hartree–Fock–Bogoliubov mass model. We make use of corresponding fission barrier heights and compare the impact of four different fission fragment distribution models on the final r-process abundance distribution. In particular, we explore the abundance distribution in the second r-process peak and the rare-earth sub-peak as a function of mass models and fission fragment distributions, as well as the origin of a shift in the third r-process peak position. The latter has been noticed in a number of merger nucleosynthesis predictions. We show that the shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)–(γ,n) equilibrium is no longer maintained. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of β-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well.

Simulated East-west differences in F-region peak electron density at Far East mid-latitude region

Science.gov (United States)

Ren, Z.; Wan, W.

2017-12-01

In the present work, using Three-Dimensional Theoretical Ionospheric Model of the Earth in Institute of Geology and Geophysics, Chinese Academy of Sciences (TIME3D-IGGCAS), we simulated the east-west differences in Fregion peak electron density (NmF2) at Far East mid-latitude region.We found that, after removing the longitudinal variations of neutral parameters, TIME3D-IGGCAS can better represent the observed relative east-west difference (Rew) features. Rew is mainly negative (West NmF2 > East NmF2) at noon and positive (East NmF2 >West NmF2) at evening-night. The magnitude of daytime negative Rew is weak at local winter and strong at local summer, and the daytime Rew show two negative peaks around two equinoxes. With the increasing of solar flux level, the magnitude of Rew mainly become larger, and two daytime negative peaks slight shifts to June Solstice. With the decreasing of geographical latitude, Rew mainly become positive, and two daytime negative peaks slight shifts to June Solstice. Our simulation also suggested that the thermospheric zonal wind combined with the geomagnetic field configuration play a pivotal role in the formation of the ionospheric east-west differences at Far East midlatitude region.

SU-E-T-553: Monte Carlo Calculation of Proton Bragg Peak Displacements in the Presence of Al2O3:C Dosimeters

Energy Technology Data Exchange (ETDEWEB)

Young, L; Yang, F [Univ Washington, Seattle, WA (United States)

2015-06-15

Purpose: The application of optically stimulated luminescence dosimeters (OSLDs) may be extended to clinical investigations verifying irradiated doses in small animal models. In proton beams, the accurate positioning of the Bragg peak is essential for tumor targeting. The purpose of this study was to estimate the displacement of a pristine Bragg peak when an Al2O3:C nanodot (Landauer, Inc.) is placed on the surface of a water phantom and to evaluate corresponding changes in dose. Methods: Clinical proton pencil beam simulations were carried out with using TOPAS, a Monte Carlo platform layered on top of GEANT4. Point-shaped beams with no energy spread were modeled for energies 100MV, 150MV, 200MV, and 250MV. Dose scoring for 100,000 particle histories was conducted within a water phantom (20cm × 20cm irradiated area, 40cm depth) with its surface placed 214.5cm away from the source. The modeled nanodot had a 4mm radius and 0.2mm thickness. Results: A comparative analysis of Monte Carlo depth dose profiles modeled for these proton pencil beams did not demonstrate an energy dependent in the Bragg peak shift. The shifts in Bragg Peak depth for water phantoms modeled with a nanodot on the phantom surface ranged between 2.7 to 3.2 mm. In all cases, the Bragg Peaks were shifted closer to the irradiation source. The peak dose in phantoms with an OSLD remained unchanged with percent dose differences less than 0.55% when compared to phantom doses without the nanodot. Conclusion: Monte Carlo calculations show that the presence of OSLD nanodots in proton beam therapy will not change the position of a pristine Bragg Peak by more than 3 mm. Although the 3.0 mm shift will not have a detrimental effect in patients receiving proton therapy, this effect may not be negligible in dose verification measurements for mouse models at lower proton beam energies.

Hydrogen exchange rate of tyrosine hydroxyl groups in proteins as studied by the deuterium isotope effect on C(zeta) chemical shifts.

Science.gov (United States)

Takeda, Mitsuhiro; Jee, Jungoo; Ono, Akira Mei; Terauchi, Tsutomu; Kainosho, Masatsune

2009-12-30

We describe a new NMR method for monitoring the individual hydrogen exchange rates of the hydroxyl groups of tyrosine (Tyr) residues in proteins. The method utilizes (2S,3R)-[beta(2),epsilon(1,2)-(2)H(3);0,alpha,beta,zeta-(13)C(4);(15)N]-Tyr, zeta-SAIL Tyr, to detect and assign the (13)C(zeta) signals of Tyr rings efficiently, either by indirect (1)H-detection through 7-8 Hz (1)H(delta)-(13)C(zeta) spin couplings or by direct (13)C(zeta) observation. A comparison of the (13)C(zeta) chemical shifts of three Tyr residues of an 18.2 kDa protein, EPPIb, dissolved in H(2)O and D(2)O, revealed that all three (13)C(zeta) signals in D(2)O appeared at approximately 0.13 ppm ( approximately 20 Hz at 150.9 MHz) higher than those in H(2)O. In a H(2)O/D(2)O (1:1) mixture, however, one of the three signals for (13)C(zeta) appeared as a single peak at the averaged chemical shifts, and the other two appeared as double peaks at exactly the same chemical shifts in H(2)O and D(2)O, in 50 mM phosphate buffer (pH 6.6) at 40 degrees C. These three peaks were assigned to Tyr-36, Tyr-120, and Tyr-30, from the lower to higher chemical shifts, respectively. The results indicate that the hydroxyl proton of Tyr-120 exchanges faster than a few milliseconds, whereas those of Tyr-30 and Tyr-36 exchange more slowly. The exchange rate of the Tyr-30 hydroxyl proton, k(ex), under these conditions was determined by (13)C NMR exchange spectroscopy (EXSY) to be 9.2 +/- 1.1 s(-1). The Tyr-36 hydroxyl proton, however, exchanges too slowly to be determined by EXSY. These profound differences among the hydroxyl proton exchange rates are closely related to their relative solvent accessibility and the hydrogen bonds associated with the Tyr hydroxyl groups in proteins.

Escape peak ratios in silicon X-ray charge coupled devices (CCDs)

International Nuclear Information System (INIS)

McCarthy, K.J.; Owens, A.; Keay, A.

1997-01-01

The intensity of the escape peak from the CCDs developed for the Joint European X-ray Telescope (JET-X) has been investigated over the energy range 2-10 keV. Both measured and calculated escape peak ratios (i.e., the ratio of counts in the escape peak to the sum of the counts in the escape and main peaks) are found to be in excellent agreement for all event sizes (i.e., single pixel events, 1 and 2 pixel events, etc.). Using a Monte Carlo simulation the escape peak ratio has been investigated as a function of pixel size and depletion depth. For completeness, we list the energy dependent parameterised forms for five CCDs used in three major astronomy missions. (orig.)

Optimization of a Compton-suppression system by escape-peak ratio

International Nuclear Information System (INIS)

Niu, H.; Chao, J.H.; Wu, S.-C.

1996-01-01

A Compton-suppression system consisting of an HPGe central detector surrounded by eight BGO scintillators in an annular geometry was assembled. This system is dedicated to in-beam γ-ray measurements. The ratios of full-energy to single-escape peak and full-energy of double-escape peak, at γ-rays of 2754, 4443 and 6130 keV, were used to derive associated suppression factors in order to optimize detection conditions of the system. The suppression factors derived both from the escape peak ratios and the corresponding peak-to-Compton ratios of the γ-ray spectra are compared and discussed. This optimization technique may be of great significance for analyzing complicated spectra, where high-energy γ-rays are considered for analytical use. (Author)

A quantitative trait locus mixture model that avoids spurious LOD score peaks.

Science.gov (United States)

Feenstra, Bjarke; Skovgaard, Ib M

2004-06-01

In standard interval mapping of quantitative trait loci (QTL), the QTL effect is described by a normal mixture model. At any given location in the genome, the evidence of a putative QTL is measured by the likelihood ratio of the mixture model compared to a single normal distribution (the LOD score). This approach can occasionally produce spurious LOD score peaks in regions of low genotype information (e.g., widely spaced markers), especially if the phenotype distribution deviates markedly from a normal distribution. Such peaks are not indicative of a QTL effect; rather, they are caused by the fact that a mixture of normals always produces a better fit than a single normal distribution. In this study, a mixture model for QTL mapping that avoids the problems of such spurious LOD score peaks is presented.

On the energy shift of the ECC cusp. Does the shift really exist?

International Nuclear Information System (INIS)

Barrachina, R.O.; Sarkadi, L.

2004-01-01

Full text: The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions is generally thought to be a divergence. The peak is centered at electron velocity that matches that of the projectile. Recently Illescas et al. [1] claimed, however, that 'the cusp is not a divergence smoothed by the experiment, and is slightly shifted from the impact-velocity value'. In a subsequent work Shah et al. [2] measured the ECC cusp for collisions of 10- and 20- keV protons with H2 and He, and found that the peak was indeed shifted to a velocity below its expected position. Their classical trajectory Monte Carlo (CTMC) calculations reproduced the observation well. In the present work we demonstrate by our CTMC calculations (made for the case of 20-keV protons on He) that the intensity, width and position of the ECC cusp do depend on the experimental conditions by which the electrons are detected (first of all, the acceptance angle of the electron spectrometer). We also present experimental data for this collision system. While the latter data are well reproduced by our CTMC calculations, neither the theoretical results, nor the experimental data of the present work support of the findings of Shah et al. [2]. At the same time, analyzing the problem in the framework of the general final-state interaction theory of cusp formation [3], we concluded that 'rigorously' speaking Shah et al. [2] are right when they state that the ECC cusp is not a divergence. The divergence is smeared out by the scattering of the projectile. However, this effect is negligibly small at the lowest energy that was considered in their paper, 10 keV. At this impact energy the projectile motion is smeared within an angular region Δθ th ∼ 0.06 deg, which is much smaller than the acceptance angle of the experiment, Δθ exp ∼ 1.5 deg

NOISY WEAK-LENSING CONVERGENCE PEAK STATISTICS NEAR CLUSTERS OF GALAXIES AND BEYOND

International Nuclear Information System (INIS)

Fan Zuhui; Shan Huanyuan; Liu Jiayi

2010-01-01

Taking into account noise from intrinsic ellipticities of source galaxies, in this paper, we study the peak statistics in weak-lensing convergence maps around clusters of galaxies and beyond. We emphasize how the noise peak statistics is affected by the density distribution of nearby clusters, and also how cluster-peak signals are changed by the existence of noise. These are the important aspects to be thoroughly understood in weak-lensing analyses for individual clusters as well as in cosmological applications of weak-lensing cluster statistics. We adopt Gaussian smoothing with the smoothing scale θ G = 0.5arcmin in our analyses. It is found that the noise peak distribution near a cluster of galaxies sensitively depends on the density profile of the cluster. For a cored isothermal cluster with the core radius R c , the inner region with R ≤ R c appears noisy containing on average ∼2.4 peaks with ν ≥ 5 for R c = 1.7arcmin and the true peak height of the cluster ν = 5.6, where ν denotes the convergence signal-to-noise ratio. For a Navarro-Frenk-White (NFW) cluster of the same mass and the same central ν, the average number of peaks with ν ≥ 5 within R ≤ R c is ∼1.6. Thus a high peak corresponding to the main cluster can be identified more cleanly in the NFW case. In the outer region with R c c , the number of high noise peaks is considerably enhanced in comparison with that of the pure noise case without the nearby cluster. For ν ≥ 4, depending on the treatment of the mass-sheet degeneracy in weak-lensing analyses, the enhancement factor f is in the range of ∼5 to ∼55 for both clusters as their outer density profiles are similar. The properties of the main-cluster-peak identified in convergence maps are also significantly affected by the presence of noise. Scatters as well as a systematic shift for the peak height are present. The height distribution is peaked at ν ∼ 6.6, rather than at ν = 5.6, corresponding to a shift of Δν ∼ 1

Nonlocal optical effects on the Goos–Hänchen shifts at multilayered hyperbolic metamaterials

International Nuclear Information System (INIS)

Chen, Chih-Wei; Bian, Tingting; Chiang, Hai-Pang; Leung, P T

2016-01-01

The lateral beam shift of light incident on a multilayered hyperbolic metamaterial (HMM) is investigated using a theoretical model which emphasizes the nonlocal optical response of the indefinite material. By applying an effective local response theory formulated recently in the literature, it is found that nonlocal effects only affect p polarized light in this Goos–Hänchen (GH) shift of the incident beam; leading to a blue-shifted peak for positive shifts at high frequencies and red-shifted dip for negative shifts at low frequencies in the GH shift spectrum. An account for the observed phenomenon is given by referring to the ‘Brewster condition’ for the reflected wave from the HMM. This observation thus provides a relatively direct probe for the nonlocal response of the HMM. (paper)

Optical Characterization and Applications of Single Walled Carbon Nanotubes

Science.gov (United States)

Strano, Michael S.

2005-03-01

Recent advances in the dispersion and separation of single walled carbon nanotubes have led to new methods of optical characterization and some novel applications. We find that Raman spectroscopy can be used to probe the aggregation state of single-walled carbon nanotubes in solution or as solids with a range of varying morphologies. Carbon nanotubes experience an orthogonal electronic dispersion when in electrical contact that broadens (from 40 meV to roughly 80 meV) and shifts the interband transition to lower energy (by 60 meV). We show that the magnitude of this shift is dependent on the extent of bundle organization and the inter-nanotube contact area. In the Raman spectrum, aggregation shifts the effective excitation profile and causes peaks to increase or decrease, depending on where the transition lies, relative to the excitation wavelength. The findings are particularly relevant for evaluating nanotube separation processes, where relative peak changes in the Raman spectrum can be confused for selective enrichment. We have also used gel electrophoresis and column chromatography conducted on individually dispersed, ultrasonicated single-walled carbon nanotubes to yield simultaneous separation by tube length and diameter. Electroelution after electrophoresis is shown to produce highly resolved fractions of nanotubes with average lengths between 92 and 435 nm. Separation by diameter is concomitant with length fractionation, and nanotubes that have been cut shortest also possess the greatest relative enrichments of large-diameter species. The relative quantum yield decreases nonlinearly as the nanotube length becomes shorter. These findings enable new applications of nanotubes as sensors and biomarkers. Particularly, molecular detection using near infrared (n-IR) light between 0.9 and 1.3 eV has important biomedical applications because of greater tissue penetration and reduced auto-fluorescent background in thick tissue or whole blood media. Carbon nanotubes

The application of spatial shifting for peak-to-average power ratio reduction in MIMO OFDM systems

NARCIS (Netherlands)

Schenk, T.C.W.; Smulders, P.F.M.; Fledderus, E.

2006-01-01

This paper investigates the application of spatial shifting (SS) of partial transmit sequences (PTSs) in multiple-input multiple-output OFDM. The technique rearranges the transmit (TX) vector in such a way that subparts are transmitted on those TX branches that result in the lowest overall

[A peak recognition algorithm designed for chromatographic peaks of transformer oil].

Science.gov (United States)

Ou, Linjun; Cao, Jian

2014-09-01

In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

International Nuclear Information System (INIS)

Maldonado, Delis

2012-01-01

The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

Assessing peak aerobic capacity in Dutch law enforcement officers

Directory of Open Access Journals (Sweden)

Harriet Wittink

2015-06-01

Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

Association between exposure to rotating night shift versus day shift using levels of 6-sulfatoxymelatonin and cortisol and other sex hormones in women.

Science.gov (United States)

Gómez-Acebo, Inés; Dierssen-Sotos, Trinidad; Papantoniou, Kyriaki; García-Unzueta, María Teresa; Santos-Benito, María Francisca; Llorca, Javier

2015-02-01

The present study aims to compare 6-sulfatoxymelatonin (aMT6s) secretion patterns and levels of cortisol and sex hormones (estradiol, progesterone, DHEA, DHEAS, and testosterone) among rotating night-shift workers and day-shift workers. We performed a cross-sectional study in Cantabria (northern Spain) including 136 women (73 day-shift workers and 63 rotating night-shift workers). Blood and urine samples were obtained after two consecutive working days. Differences in means were estimated using ANCOVA, stratified by menopausal status, ovulation phase, and adjusted for season, age, body mass index, consumption of cigarettes in the last 24 h. aMT6s circadian rhythm was analyzed using the cosinor analysis. The present study showed that rotating night-shift workers had lower excretion of aMT6s than day-shift workers (mesor = 50.26 ng aMT6s/mg creatinine in women with rotating night shift versus 88.79 ng aMT6s/mg creatinine in women with day shift), lower fluctuation (amplitude = 45.24 ng aMT6s/mg creatinine in rotating night-shift workers versus 79.71 ng aMT6s/mg creatinine in day-shift workers), and a later acrophase (aMT6s peak time: 08:31 in rotating night-shift workers versus 07:13 h in day-shift workers). Additionally, women with rotating night shift had higher estradiol and progesterone levels, compared to day workers, especially in the follicular phase on the menstrual cycle.

Phase-Shifted Eccentric Core Fiber Bragg Grating Fabricated by Electric Arc Discharge for Directional Bending Measurement

Directory of Open Access Journals (Sweden)

Yang Ouyang

2018-04-01

Full Text Available A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG fabricated by electric arc discharge (EAD is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m−1 and −51.5 pm/m−1, respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively.

Comparison of public peak detection algorithms for MALDI mass spectrometry data analysis.

Science.gov (United States)

Yang, Chao; He, Zengyou; Yu, Weichuan

2009-01-06

In mass spectrometry (MS) based proteomic data analysis, peak detection is an essential step for subsequent analysis. Recently, there has been significant progress in the development of various peak detection algorithms. However, neither a comprehensive survey nor an experimental comparison of these algorithms is yet available. The main objective of this paper is to provide such a survey and to compare the performance of single spectrum based peak detection methods. In general, we can decompose a peak detection procedure into three consequent parts: smoothing, baseline correction and peak finding. We first categorize existing peak detection algorithms according to the techniques used in different phases. Such a categorization reveals the differences and similarities among existing peak detection algorithms. Then, we choose five typical peak detection algorithms to conduct a comprehensive experimental study using both simulation data and real MALDI MS data. The results of comparison show that the continuous wavelet-based algorithm provides the best average performance.

Spin-wave propagation and spin-polarized electron transport in single-crystal iron films

Science.gov (United States)

Gladii, O.; Halley, D.; Henry, Y.; Bailleul, M.

2017-11-01

The techniques of propagating spin-wave spectroscopy and current-induced spin-wave Doppler shift are applied to a 20-nm-thick Fe/MgO(001) film. The magnetic parameters extracted from the position of the spin-wave resonance peaks are very close to those tabulated for bulk iron. From the zero-current propagating wave forms, a group velocity of 4 km/s and an attenuation length of about 6 μ m are extracted for 1.6-μ m -wavelength spin wave at 18 GHz. From the measured current-induced spin-wave Doppler shift, we extract a surprisingly high degree of spin polarization of the current of 83 % , which constitutes the main finding of this work. This set of results makes single-crystalline iron a promising candidate for building devices utilizing high-frequency spin waves and spin-polarized currents.

Effects of equipment and technique on peak flow measurements

Directory of Open Access Journals (Sweden)

O'Driscoll B Ronan

2006-06-01

Full Text Available Abstract Background Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients. Methods We studied 36 subjects (PEF range 80–570 l/min. All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique or a forced maximal expiration to residual volume (FVC technique. Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer. Results The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p Conclusion Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.

PeakSeeker: a program for interpreting genotypes of mononucleotide repeats

Directory of Open Access Journals (Sweden)

Salipante Stephen J

2009-02-01

Full Text Available Abstract Background Mononucleotide repeat microsatellites are abundant, highly polymorphic DNA sequences, having the potential to serve as valuable genetic markers. Use of mononucleotide microsatellites has been limited by their tendency to produce "stutter", confounding signals from insertions and deletions within the mononucleotide tract that occur during PCR, which complicates interpretation of genotypes by masking the true position of alleles. Consequently, microsatellites with larger repeating subunits (dinucleotide and trinucleotide motifs are used, which produce less stutter but are less genetically heterogeneous and less informative. A method to interpret the genotypes of mononucleotide repeats would permit the widespread use of those highly informative microsatellites in genetic research. Findings We have developed an approach to interpret genotypes of mononucleotide repeats using a software program, named PeakSeeker. PeakSeeker interprets experimental electropherograms as the most likely product of signals from individual alleles. Because mononucleotide tracts demonstrate locus-specific patterns of stutter peaks, this approach requires that the genotype pattern from a single allele is defined for each marker, which can be approximated by genotyping single DNA molecules or homozygotes. We have evaluated the program's ability to discriminate various types of homozygous and heterozygous mononucleotide loci using simulated and experimental data. Conclusion Mononucleotide tracts offer significant advantages over di- and tri-nucleotide microsatellite markers traditionally employed in genetic research. The PeakSeeker algorithm provides a high-throughput means to type mononucleotide tracts using conventional and widely implemented fragment length polymorphism genotyping. Furthermore, the PeakSeeker algorithm could potentially be adapted to improve, and perhaps to standardize, the analysis of conventional microsatellite genotypes.

The role of fission on neutron star mergers and its impact on the r-process peaks

International Nuclear Information System (INIS)

Eichler, M.; Thielemann, F.-K.; Arcones, A.; Langanke, K.; Martinez-Pinedo, G.; Kelic, A.; Korobkin, O.; Rosswog, S.; Marketin, T.; Panov, I.; Rauscher, T.; Winteler, C.; Zinner, N. T.

2016-01-01

The comparison between observational abundance features and those obtained from nucleosynthesis predictions of stellar evolution and/or explosion simulations can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. Here we test the abundance features of r-process nucleosynthesis calculations using four different fission fragment distribution models. Furthermore, we explore the origin of a shift in the third r-process peak position in comparison with the solar r-process abundances which has been noticed in a number of merger nucleosynthesis predictions. We show that this shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)-(γ,n) equilibrium is not maintained anymore. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of β-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well.

The role of fission on neutron star mergers and its impact on the r-process peaks

Energy Technology Data Exchange (ETDEWEB)

Eichler, M., E-mail: marius.eichler@unibas.ch; Thielemann, F.-K. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4055 Basel (Switzerland); Arcones, A.; Langanke, K.; Martinez-Pinedo, G. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 2, D-64289 Darmstadt (Germany); GSI Helmholtzzentrum fr Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Kelic, A. [GSI Helmholtzzentrum fr Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Korobkin, O.; Rosswog, S. [The Oskar Klein Centre, Department of Astronomy, AlbaNova, Stockholm University, SE-10691 Stockholm (Sweden); Marketin, T. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Panov, I. [SSC RF ITEP of NRC “Kurchatov Institute”, Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4055 Basel (Switzerland); Rauscher, T. [Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4055 Basel (Switzerland); Winteler, C. [Institut Energie am Bau, Fachhochschule Nordwestschweiz, St. Jakobs-Strasse 84, 4132 Muttenz (Switzerland); Zinner, N. T. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, bygn. 1520, DK-8000 Aarhus C (Denmark)

2016-06-21

The comparison between observational abundance features and those obtained from nucleosynthesis predictions of stellar evolution and/or explosion simulations can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. Here we test the abundance features of r-process nucleosynthesis calculations using four different fission fragment distribution models. Furthermore, we explore the origin of a shift in the third r-process peak position in comparison with the solar r-process abundances which has been noticed in a number of merger nucleosynthesis predictions. We show that this shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)-(γ,n) equilibrium is not maintained anymore. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of β-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well.

Fatigue affects peak joint torque angle in hamstrings but not in quadriceps.

Science.gov (United States)

Coratella, Giuseppe; Bellin, Giuseppe; Beato, Marco; Schena, Federico

2015-01-01

Primary aim of this study was to investigate peak joint torque angle (i.e. the angle of peak torque) changes recorded during an isokinetic test before and after a fatiguing soccer match simulation. Secondarily we want to investigate functional Hecc:Qconc and conventional Hconc:Qconc ratio changes due to fatigue. Before and after a standardised soccer match simulation, twenty-two healthy male amateur soccer players performed maximal isokinetic strength tests both for hamstrings and for quadriceps muscles at 1.05 rad · s(‒1), 3.14 rad · s(‒1) and 5.24 rad · s(‒1). Peak joint torque angle, peak torque and both functional Hecc:Qconc and conventional Hconc:Qconc ratios were examined. Both dominant and non-dominant limbs were tested. Peak joint torque angle significantly increased only in knee flexors. Both eccentric and concentric contractions resulted in such increment, which occurred in both limbs. No changes were found in quadriceps peak joint torque angle. Participants experienced a significant decrease in torque both in hamstrings and in quadriceps. Functional Hecc:Qconc ratio was lower only in dominant limb at higher velocities, while Hconc:Qconc did not change. This study showed after specific fatiguing task changes in hamstrings only torque/angle relationship. Hamstrings injury risk could depend on altered torque when knee is close to extension, coupled with a greater peak torque decrement compared to quadriceps. These results suggest the use eccentric based training to prevent hamstrings shift towards shorter length.

Effect of overlapping on location of peaks in qualitative X-ray fluorescent analysis

International Nuclear Information System (INIS)

Jordanov, J.; Stefanov, R.; Tsanov, T.; Jordanov, N.

1982-01-01

To determine the location of the maxima in spectra without resorting to the comparatively complex Fourier-analysis apparatus it is proposed to take into account the overlapping of two adjacent peaks. A formula for the correction of the locations of overlapping maxima with an infinitely small step has been obtained and it is recommended when using X-ray apparatus with great resolution. With flat crystal-analyser apparata, which has a comparatively small resolution, a considerable number of maxima are obtained from the overlapping of at least two adjacent peaks. For that case another formula for the estimation of the shift of the maxima's location from their tabular values is proposed. (authors)

Analysis of a micropolarizer array-based simultaneous phase-shifting interferometer.

Science.gov (United States)

Novak, Matt; Millerd, James; Brock, Neal; North-Morris, Michael; Hayes, John; Wyant, James

2005-11-10

Recent technological innovations have enabled the development of a new class of dynamic (vibration-insensitive) interferometer based on a CCD pixel-level phase-shifting approach. We present theoretical and experimental results for an interferometer based on this pixelated phase-shifting technique. Analyses of component errors and instrument functionality are presented. We show that the majority of error sources cause relatively small magnitude peak-to-valley errors in measurement of the order of 0.002-0.005lambda. These errors are largely mitigated by high-rate data acquisition and consequent data averaging.

Do Slow and Steady Residents Win the Race? Modeling the Effects of Peak and Overall Resident Productivity in the Emergency Department.

Science.gov (United States)

Joseph, Joshua W; Novack, Victor; Wong, Matthew L; Nathanson, Larry A; Sanchez, Leon D

2017-08-01

Emergency medicine residents need to be staffed in a way that balances operational needs with their educational experience. Key to developing an optimal schedule is knowing a resident's expected productivity, a poorly understood metric. We sought to measure how a resident's busiest (peak) workload affects their overall productivity for the shift. We conducted a retrospective, observational study of resident productivity at an urban, tertiary care center with a 3-year Accreditation Council for Graduate Medical Education-approved emergency medicine training program, with 55,000 visits annually. We abstracted resident productivity data from a database of patient assignments from July 1, 2010 to June 20, 2015, utilizing a generalized estimation equation method to evaluate physician shifts. Our primary outcome measure was the total number of patients seen by a resident over a shift. The secondary outcome was the number of patients seen excluding those in the peak hour. A total of 14,361 shifts were evaluated. Multivariate analysis showed that the total number of patients seen was significantly associated with the number of patients seen during the peak hour, level of training, the timing of the shift, but most prominently, lower variance in patients seen per hour (coefficient of variation productivity can be a strong predictor of their overall productivity, but the substantial negative effect of variability favors a steadier pace. This suggests that resident staffing and patient assignments should generally be oriented toward a more consistent workload, an effect that should be further investigated with attending physicians. Copyright © 2017 Elsevier Inc. All rights reserved.

Peak clustering in two-dimensional gas chromatography with mass spectrometric detection based on theoretical calculation of two-dimensional peak shapes: the 2DAid approach.

Science.gov (United States)

van Stee, Leo L P; Brinkman, Udo A Th

2011-10-28

A method is presented to facilitate the non-target analysis of data obtained in temperature-programmed comprehensive two-dimensional (2D) gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-ToF-MS). One main difficulty of GC×GC data analysis is that each peak is usually modulated several times and therefore appears as a series of peaks (or peaklets) in the one-dimensionally recorded data. The proposed method, 2DAid, uses basic chromatographic laws to calculate the theoretical shape of a 2D peak (a cluster of peaklets originating from the same analyte) in order to define the area in which the peaklets of each individual compound can be expected to show up. Based on analyte-identity information obtained by means of mass spectral library searching, the individual peaklets are then combined into a single 2D peak. The method is applied, amongst others, to a complex mixture containing 362 analytes. It is demonstrated that the 2D peak shapes can be accurately predicted and that clustering and further processing can reduce the final peak list to a manageable size. Copyright © 2011 Elsevier B.V. All rights reserved.

Peak fitting and identification software library for high resolution gamma-ray spectra

International Nuclear Information System (INIS)

Uher, Josef; Roach, Greg; Tickner, James

2010-01-01

A new gamma-ray spectral analysis software package is under development in our laboratory. It can be operated as a stand-alone program or called as a software library from Java, C, C++ and MATLAB TM environments. It provides an advanced graphical user interface for data acquisition, spectral analysis and radioisotope identification. The code uses a peak-fitting function that includes peak asymmetry, Compton continuum and flexible background terms. Peak fitting function parameters can be calibrated as functions of energy. Each parameter can be constrained to improve fitting of overlapping peaks. All of these features can be adjusted by the user. To assist with peak identification, the code can automatically measure half-lives of single or multiple overlapping peaks from a time series of spectra. It implements library-based peak identification, with options for restricting the search based on radioisotope half-lives and reaction types. The software also improves the reliability of isotope identification by utilizing Monte-Carlo simulation results.

Nodal structure and phase shifts of zero-incident-energy wave functions: Multiparticle single-channel scattering

International Nuclear Information System (INIS)

Iwinski, Z.R.; Rosenberg, L.; Spruch, L.

1986-01-01

For potential scattering, with delta/sub L/(k) the phase shift modulo π for an incident wave number k, Levinson's theorem gives delta/sub L/(0)-delta/sub L/(infinity) in terms of N/sub L/, the number of bound states of angular momentum L, for delta/sub L/(k) assumed to be a continuous function of k. N/sub L/ also determines the number of nodes of the zero-energy wave function u/sub L/(r). A knowledge of the nodal structure and of the absolute value of delta/sub L/(0) is very useful in theoretical studies of low-energy potential scattering. Two preliminary attempts, one formal and one ''physical,'' are made to extend the above results to single-channel scattering by a compound system initially in its ground state. The nodal structure will be of greater interest to us here than an extension of Levinson's theorem

Type 2 Active Galactic Nuclei with Double-peaked [O III] Lines. II. Single AGNs with Complex Narrow-line Region Kinematics are More Common than Binary AGNs

Science.gov (United States)

Shen, Yue; Liu, Xin; Greene, Jenny E.; Strauss, Michael A.

2011-07-01

Approximately 1% of low-redshift (z interpreted as either due to kinematics, such as biconical outflows and/or disk rotation of the narrow line region (NLR) around single black holes, or due to the relative motion of two distinct NLRs in a merging pair of AGNs. Here, we report follow-up near-infrared (NIR) imaging and optical slit spectroscopy of 31 double-peaked [O III] type 2 AGNs drawn from the Sloan Digital Sky Survey (SDSS) parent sample presented in Liu et al. The NIR imaging traces the old stellar population in each galaxy, while the optical slit spectroscopy traces the NLR gas. These data reveal a mixture of origins for the double-peaked feature. Roughly 10% of our objects are best explained by binary AGNs at (projected) kpc-scale separations, where two stellar components with spatially coincident NLRs are seen. ~50% of our objects have [O III] emission offset by a few kpc, corresponding to the two velocity components seen in the SDSS spectra, but there are no spatially coincident double stellar components seen in the NIR imaging. For those objects with sufficiently high-quality slit spectra, we see velocity and/or velocity dispersion gradients in [O III] emission, suggestive of the kinematic signatures of a single NLR. The remaining ~40% of our objects are ambiguous and will need higher spatial resolution observations to distinguish between the two scenarios. Our observations therefore favor the kinematics scenario with a single AGN for the majority of these double-peaked [O III] type 2 AGNs. We emphasize the importance of combining imaging and slit spectroscopy in identifying kpc-scale binary AGNs, i.e., in no cases does one of these alone allow an unambiguous identification. We estimate that ~0.5%-2.5% of the z ~ 150 km s-1. Based in part on observations obtained with the 6.5 m Magellan telescopes located at Las Campanas Observatory, Chile, and with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research

Single photon sources in 4H-SiC metal-oxide-semiconductor field-effect transistors

Science.gov (United States)

Abe, Y.; Umeda, T.; Okamoto, M.; Kosugi, R.; Harada, S.; Haruyama, M.; Kada, W.; Hanaizumi, O.; Onoda, S.; Ohshima, T.

2018-01-01

We present single photon sources (SPSs) embedded in 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs). They are formed in the SiC/SiO2 interface regions of wet-oxidation C-face 4H-SiC MOSFETs and were not found in other C-face and Si-face MOSFETs. Their bright room-temperature photoluminescence (PL) was observed in the range from 550 to 750 nm and revealed variable multi-peak structures as well as variable peak shifts. We characterized a wide variety of their PL spectra as the inevitable variation of local atomic structures at the interface. Their polarization dependence indicates that they are formed at the SiC side of the interface. We also demonstrate that it is possible to switch on/off the SPSs by a bias voltage of the MOSFET.

The spatial resolution of epidemic peaks.

Directory of Open Access Journals (Sweden)

Harriet L Mills

2014-04-01

Full Text Available The emergence of novel respiratory pathogens can challenge the capacity of key health care resources, such as intensive care units, that are constrained to serve only specific geographical populations. An ability to predict the magnitude and timing of peak incidence at the scale of a single large population would help to accurately assess the value of interventions designed to reduce that peak. However, current disease-dynamic theory does not provide a clear understanding of the relationship between: epidemic trajectories at the scale of interest (e.g. city; population mobility; and higher resolution spatial effects (e.g. transmission within small neighbourhoods. Here, we used a spatially-explicit stochastic meta-population model of arbitrary spatial resolution to determine the effect of resolution on model-derived epidemic trajectories. We simulated an influenza-like pathogen spreading across theoretical and actual population densities and varied our assumptions about mobility using Latin-Hypercube sampling. Even though, by design, cumulative attack rates were the same for all resolutions and mobilities, peak incidences were different. Clear thresholds existed for all tested populations, such that models with resolutions lower than the threshold substantially overestimated population-wide peak incidence. The effect of resolution was most important in populations which were of lower density and lower mobility. With the expectation of accurate spatial incidence datasets in the near future, our objective was to provide a framework for how to use these data correctly in a spatial meta-population model. Our results suggest that there is a fundamental spatial resolution for any pathogen-population pair. If underlying interactions between pathogens and spatially heterogeneous populations are represented at this resolution or higher, accurate predictions of peak incidence for city-scale epidemics are feasible.

Determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method in combination with magnetic spectrometers

Energy Technology Data Exchange (ETDEWEB)

Doncel, M. [Universidad de Salamanca, Laboratorio de Radiaciones Ionizantes, Salamanca (Spain); Royal Institute of Technology, Department of Physics, Stockholm (Sweden); University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Gadea, A. [CSIC-University of Valencia, Istituto de Fisica Corpuscular, Valencia (Spain); Valiente-Dobon, J.J. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Quintana, B. [Universidad de Salamanca, Laboratorio de Radiaciones Ionizantes, Salamanca (Spain); Modamio, V. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); University of Oslo, Oslo (Norway); Mengoni, D. [Dipartimento di Fisica e Astronomia, Universita di Padova, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Moeller, O.; Pietralla, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Dewald, A. [Institut fuer Kernphysik, Universitaet Koeln (Germany)

2017-10-15

The current work presents the determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method, in combination with spectrometers for ion identification, normalizing the intensity of the peaks by the ions detected in the spectrometer as a valid technique that produces results comparable to the ones obtained by the conventional shifted-to-unshifted peak ratio method. The technique has been validated using data measured with the γ-ray array AGATA, the PRISMA spectrometer and the Cologne plunger setup. In this paper a test performed with the AGATA-PRISMA setup at LNL and the advantages of this new approach with respect to the conventional Recoil Distance Doppler Shift Method are discussed. (orig.)

Quantitative optical extinction-based parametric method for sizing a single core-shell Ag-Ag2O nanoparticle

International Nuclear Information System (INIS)

Santillan, J M J; Scaffardi, L B; Schinca, D C

2011-01-01

This paper develops a parametric method for determining the core radius and shell thickness in small silver-silver-oxide core-shell nanoparticles (Nps) based on single particle optical extinction spectroscopy. The method is based on the study of the relationship between plasmon peak wavelength, full width at half maximum (FWHM) and contrast of the extinction spectra as a function of core radius and shell thickness. This study reveals that plasmon peak wavelength is strongly dependent on shell thickness, whereas FWHM and contrast depend on both variables. These characteristics may be used for establishing an easy and fast stepwise procedure to size core-shell NPs from single particle absorption spectrum. The importance of the method lies in the possibility of monitoring the growth of the silver-oxide layer around small spherical silver Nps in real time. Using the electrostatic approximation of Mie theory, core-shell single particle extinction spectra were calculated for a silver particle's core size smaller than about 20 nm and different thicknesses of silver oxide around it. Analysis of the obtained curves shows a very particular characteristic of the plasmon peak of small silver-silver-oxide Nps, expressed in the fact that its position is strongly dependent on oxide thickness and weakly dependent on the core radius. Even a very thin oxide layer shifts the plasmon peak noticeably, enabling plasmon tuning with appropriate shell thickness. This characteristic, together with the behaviour of FWHM and contrast of the extinction spectra can be combined into a parametric method for sizing both core and shell of single silver Nps in a medium using only optical information. In turn, shell thickness can be related to oxygen content in the Np's surrounding media. The method proposed is applied to size silver Nps from single particle extinction spectrum. The results are compared with full optical spectrum fitting using the electrostatic approximation in Mie theory. The method

Peak shifts due to B(*)-B(*) rescattering in Υ(5S) dipion transitions

International Nuclear Information System (INIS)

Meng Ce; Chao Kuangta

2008-01-01

We study the energy distributions of dipion transitions Υ(5S) to Υ(1S,2S,3S)π + π - in the final-state rescattering model. Since the Υ(5S) is well above the open bottom thresholds, the dipion transitions are expected to mainly proceed through the real processes Υ(5S)→B ( * ) B ( * ) and B ( * ) B ( * ) →Υ(1S,2S,3S)π + π - . We find that the energy distributions of Υ(1S,2S,3S)π + π - markedly differ from that of Υ(5S)→B ( * ) B ( * ) . In particular, the resonance peak will be pushed up by about 7-20 MeV for these dipion transitions relative to the main hadronic decay modes. These predictions can be used to test the final-state rescattering mechanism in hadronic transitions for heavy quarkonia above the open flavor thresholds.

Accurate conjugate gradient methods for families of shifted systems

NARCIS (Netherlands)

Eshof, J. van den; Sleijpen, G.L.G.

2003-01-01

We consider the solution of the linear system (ATA + σI)xσ = ATb, for various real values of σ. This family of shifted systems arises, for example, in Tikhonov regularization and computations in lattice quantum chromodynamics. For each single shift σ this system can be solved using the conjugate

The impact of shift work on the psychological and physical health of nurses in a general hospital: a comparison between rotating night shifts and day shifts.

Science.gov (United States)

Ferri, Paola; Guadi, Matteo; Marcheselli, Luigi; Balduzzi, Sara; Magnani, Daniela; Di Lorenzo, Rosaria

2016-01-01

Shift work is considered necessary to ensure continuity of care in hospitals and residential facilities. In particular, the night shift is one of the most frequent reasons for the disruption of circadian rhythms, causing significant alterations of sleep and biological functions that can affect physical and psychological well-being and negatively impact work performance. The aim of this study was to highlight if shift work with nights, as compared with day work only, is associated with risk factors predisposing nurses to poorer health conditions and lower job satisfaction. This cross-sectional study was conducted from June 1, 2015 to July 31, 2015 in 17 wards of a general hospital and a residential facility of a northern Italian city. This study involved 213 nurses working in rotating night shifts and 65 in day shifts. The instrument used for data collection was the "Standard Shift Work Index," validated in Italian. Data were statistically analyzed. The response rate was 86%. The nurses engaged in rotating night shifts were statistically significantly younger, more frequently single, and had Bachelors and Masters degrees in nursing. They reported the lowest mean score in the items of job satisfaction, quality and quantity of sleep, with more frequent chronic fatigue, psychological, and cardiovascular symptoms in comparison with the day shift workers, in a statistically significant way. Our results suggest that nurses with rotating night schedule need special attention due to the higher risk for both job dissatisfaction and undesirable health effects.

Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production.

Science.gov (United States)

Kordi, Mehdi; Goodall, Stuart; Barratt, Paul; Rowley, Nicola; Leeder, Jonathan; Howatson, Glyn

2017-08-01

From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task. Copyright © 2017 Elsevier Ltd. All rights reserved.

Near-infrared magneto-optical study of excitonic states in single-walled carbon nanotubes under ultra-high magnetic fields

International Nuclear Information System (INIS)

Yokoi, H; Effendi, Mukhtar; Minami, N; Takeyama, S

2011-01-01

Singlet excitonic states at the first subband-edge in single-walled carbon nanotubes (SWCNTs) have been studied through near-infrared magneto-absorption spectroscopy under magnetic fields to 105.9 T. Well-resolved absorption spectra of stretch-aligned SWCNT(CoMoCAT)-gelatin films were obtained above 100 T. By the application of magnetic fields in parallel to the alignment of SWCNTs, peak shift toward the lower energy was observed for (8, 4) and (7, 6) tubes and the opposite behavior was observed for (7, 5) and (6, 5) tubes. Above 28.8 T, new peaks emerged at the higher energy side of the peak for the (8, 4) and (7, 6) tubes, and at the lower energy side of the peaks for the (7, 5) and (6, 5) tubes. The magnetic splitting between the existing peak and the new peak was symmetric for every tube, which is in line with the energy splitting due to the Aharonov-Bohm effect. Judging from the energetic positions where the new peaks emerged, the singlet dark excitonic state locates at the lower energy than the singlet bright one in the (7, 5) and (6, 5) tubes while it is suggested strongly that the bright one locates at the lower energy in the (8, 4) and (7, 6) tubes.

WaVPeak: Picking NMR peaks through wavelet-based smoothing and volume-based filtering

KAUST Repository

Liu, Zhi

2012-02-10

Motivation: Nuclear magnetic resonance (NMR) has been widely used as a powerful tool to determine the 3D structures of proteins in vivo. However, the post-spectra processing stage of NMR structure determination usually involves a tremendous amount of time and expert knowledge, which includes peak picking, chemical shift assignment and structure calculation steps. Detecting accurate peaks from the NMR spectra is a prerequisite for all following steps, and thus remains a key problem in automatic NMR structure determination. Results: We introduce WaVPeak, a fully automatic peak detection method. WaVPeak first smoothes the given NMR spectrum by wavelets. The peaks are then identified as the local maxima. The false positive peaks are filtered out efficiently by considering the volume of the peaks. WaVPeak has two major advantages over the state-of-the-art peak-picking methods. First, through wavelet-based smoothing, WaVPeak does not eliminate any data point in the spectra. Therefore, WaVPeak is able to detect weak peaks that are embedded in the noise level. NMR spectroscopists need the most help isolating these weak peaks. Second, WaVPeak estimates the volume of the peaks to filter the false positives. This is more reliable than intensity-based filters that are widely used in existing methods. We evaluate the performance of WaVPeak on the benchmark set proposed by PICKY (Alipanahi et al., 2009), one of the most accurate methods in the literature. The dataset comprises 32 2D and 3D spectra from eight different proteins. Experimental results demonstrate that WaVPeak achieves an average of 96%, 91%, 88%, 76% and 85% recall on 15N-HSQC, HNCO, HNCA, HNCACB and CBCA(CO)NH, respectively. When the same number of peaks are considered, WaVPeak significantly outperforms PICKY. The Author(s) 2012. Published by Oxford University Press.

Direct observation of the hydrogen peak in the energy distribution of electrons backscattered elastically from polyethylene

International Nuclear Information System (INIS)

Varga, D.; Toekesi, K.; Berenyi, Z.; Toth, J.; Koever, L.

2004-01-01

Complete text of publication follows. Observation of the hydrogen peak is either challenging or impossible task for the conventional electron spectroscopy. Hydrogen was observed earlier in electron scattering experiments using transmission geometry and formvar film. In this work we show an alternative way for the detection of hydrogen peak analyzing the spectra of elastically backscattered electrons from polyethylene ((CH 2 ) n ). We take advantage of the fact that the elastic peak from polyethylene split into carbon and hydrogen components. The energy of the elastically scattered electrons is shifted from the nominal values due to the energy transfer between the primary electron and the target atoms (recoil effect). Due to the motion of the scattering atoms, a broadering of the energy width of the spectra takes place. We performed Monte Carlo simulation for 2 keV electrons penetrated and elastically backscattered from polyethylene sample. In our calculations both the elastic and inelastic scattering events were taken into account. We further assume that the thermal motion of the target atoms follows the Maxwell-Boltzmann energy distribution. After each elastic scattering the recoil energy was calculated according to ref Fig. 1 shows the geometric configuration used in the calculation. The initial angle of incident beam (θ) was 50 deg. Fig. 2 shows the gray scale plot of the intensity of electrons backscattered elastically from polyethylene. The separation between the carbon and hydrogen peaks is clearly seen. Our results show that the multiple electron scattering causes only minor changes in the energy shifts and broadenings of elastic peaks. Moreover, our simulations are in good agreement with our experimental observations. (author)

Detecting CP violation in a single neutrino oscillation channel at very long baselines

International Nuclear Information System (INIS)

Latimer, D. C.; Escamilla, J.; Ernst, D. J.

2007-01-01

We propose a way of detecting CP violation in a single neutrino oscillation channel at very long baselines (on the order of several thousands of kilometers), given precise knowledge of the smallest mass-squared difference. It is shown that CP violation can be characterized by a shift in L/E of the peak oscillation in the ν e -ν μ appearance channel, both in vacuum and in matter. In fact, matter effects enhance the shift at a fixed energy. We consider the case in which sub-GeV neutrinos are measured with varying baseline and also the case of a fixed baseline. For the varied baseline, accurate knowledge of the absolute neutrino flux would not be necessary; however, neutrinos must be distinguishable from antineutrinos. For the fixed baseline, it is shown that CP violation can be distinguished if the mixing angle θ 13 were known

Red photoluminescence and band edge shift from ZnO thin films

International Nuclear Information System (INIS)

Marotti, Ricardo E.; Badan, Juan A.; Quagliata, Eduardo; Dalchiele, Enrique A.

2007-01-01

The red photoluminescence (PL) band (peaked between 610 and 640 nm) from electrochemically deposited ZnO thin films is studied. The absorption coefficient is obtained from diffuse reflectance measurements. The absorption band edge depends on deposition conditions. The PL peak follows the shift of the band edge. A similar correlation appears when cooling down to 20 K. This suggests that PL is due to a transition from an intrinsic shallow state to an intrinsic deep state. Comparing against ZnO samples showing green PL, the shallow nature of the state is confirmed

Peak-interviewet

DEFF Research Database (Denmark)

Raalskov, Jesper; Warming-Rasmussen, Bent

Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...... fokuspersonen ønsker at tage op (nye mål eller nye processer). Nærværende workingpaper beskriver, hvad der menes med et peak-interview, peakinterviwets teoretiske fundament samt metodikken til at foretage et tillidsfuldt og effektiv peak-interview....

Chinese emissions peak: Not when, but how

International Nuclear Information System (INIS)

Spencer, Thomas; Colombier, Michel; Wang, Xin; Sartor, Oliver; Waisman, Henri

2016-07-01

It seems highly likely that China will overachieve its 2020 and 2030 targets, and peak its emissions before 2030 and possibly at a lower level than often assumed. This paper argues that the debate on the timing of the peak is misplaced: what matters is not when by why. For the peak to be seen as a harbinger of deep transformation, it needs to be based on significant macro-economic reform and restructuring, with attendant improvement in energy intensity. The Chinese economic model has been extraordinarily investment and resource intensive, and has driven the growth in GHG emissions. That model is no longer economically or environmentally sustainable. Therefore Chinese policy-makers are faced with a trade-off between slower short-term growth and economic reform, versus supporting short-term growth but slowing economic reform. The outcome will be crucial for the transition to a low-carbon economy. Overall, the 13. FYP (2016-2020) gives the impression of a cautious reflection of the new normal paradigm on the economic front, and a somewhat conservative translation of this shift into the energy and climate targets. Nonetheless, the 13. FYP targets set China well on the way to overachieving its 2020 pledge undertaken at COP15 in Copenhagen, and to potentially overachieving its INDC. It thus seems likely that China will achieve its emissions peak before 2030. However, the crucial question is not when China peaks, but whether the underlying transformation of the Chinese economy and energy system lays the basis for deep decarbonization thereafter. Thorough assessments of the implications of the 'new normal' for Chinese emissions and energy system trajectories, taking into account the link with the Chinese macro-economy, are needed. Scenarios provide a useful framework and should focus on a number of short-term uncertainties. Most energy system and emissions scenarios published today assume a continuity of trends between 2010-2015 and 2015-2020, which is at odds with clear

Spectral stability of shifted states on star graphs

Science.gov (United States)

Kairzhan, Adilbek; Pelinovsky, Dmitry E.

2018-03-01

We consider the nonlinear Schrödinger (NLS) equation with the subcritical power nonlinearity on a star graph consisting of N edges and a single vertex under generalized Kirchhoff boundary conditions. The stationary NLS equation may admit a family of solitary waves parameterized by a translational parameter, which we call the shifted states. The two main examples include (i) the star graph with even N under the classical Kirchhoff boundary conditions and (ii) the star graph with one incoming edge and N  -  1 outgoing edges under a single constraint on coefficients of the generalized Kirchhoff boundary conditions. We obtain the general counting results on the Morse index of the shifted states and apply them to the two examples. In the case of (i), we prove that the shifted states with even N ≥slant 4 are saddle points of the action functional which are spectrally unstable under the NLS flow. In the case of (ii), we prove that the shifted states with the monotone profiles in the N  -  1 edges are spectrally stable, whereas the shifted states with non-monotone profiles in the N  -  1 edges are spectrally unstable, the two families intersect at the half-soliton states which are spectrally stable but nonlinearly unstable under the NLS flow. Since the NLS equation on a star graph with shifted states can be reduced to the homogeneous NLS equation on an infinite line, the spectral instability of shifted states is due to the perturbations breaking this reduction. We give a simple argument suggesting that the spectrally stable shifted states in the case of (ii) are nonlinearly unstable under the NLS flow due to the perturbations breaking the reduction to the homogeneous NLS equation.

Multidetector calibration for mass spectrometers

International Nuclear Information System (INIS)

Bayne, C.K.; Donohue, D.L.; Fiedler, R.

1994-06-01

The International Atomic Energy Agency's Safeguards Analytical Laboratory has performed calibration experiments to measure the different efficiencies among multi-Faraday detectors for a Finnigan-MAT 261 mass spectrometer. Two types of calibration experiments were performed: (1) peak-shift experiments and (2) peak-jump experiments. For peak-shift experiments, the ion intensities were measured for all isotopes of an element in different Faraday detectors. Repeated measurements were made by shifting the isotopes to various Faraday detectors. Two different peak-shifting schemes were used to measure plutonium (UK Pu5/92138) samples. For peak-jump experiments, ion intensities were measured in a reference Faraday detector for a single isotope and compared with those measured in the other Faraday detectors. Repeated measurements were made by switching back-and-forth between the reference Faraday detector and a selected Faraday detector. This switching procedure is repeated for all Faraday detectors. Peak-jump experiments were performed with replicate measurements of 239 Pu, 187 Re, and 238 U. Detector efficiency factors were estimated for both peak-jump and peak-shift experiments using a flexible calibration model to statistically analyze both types of multidetector calibration experiments. Calculated detector efficiency factors were shown to depend on both the material analyzed and the experimental conditions. A single detector efficiency factor is not recommended for each detector that would be used to correct routine sample analyses. An alternative three-run peak-shift sample analysis should be considered. A statistical analysis of the data from this peak-shift experiment can adjust the isotopic ratio estimates for detector differences due to each sample analysis

'Peak oil' or 'peak demand'?

International Nuclear Information System (INIS)

Chevallier, Bruno; Moncomble, Jean-Eudes; Sigonney, Pierre; Vially, Rolland; Bosseboeuf, Didier; Chateau, Bertrand

2012-01-01

This article reports a workshop which addressed several energy issues like the objectives and constraints of energy mix scenarios, the differences between the approaches in different countries, the cost of new technologies implemented for this purposes, how these technologies will be developed and marketed, which will be the environmental and societal acceptability of these technical choices. Different aspects and issues have been more precisely presented and discussed: the peak oil, development of shale gases and their cost (will non conventional hydrocarbons modify the peak oil and be socially accepted?), energy efficiency (its benefits, its reality in France and other countries, its position in front of the challenge of energy transition), and strategies in the transport sector (challenges for mobility, evolution towards a model of sustainable mobility)

Phase-shift calculation using continuum-discretized states

International Nuclear Information System (INIS)

Suzuki, Y.; Horiuchi, W.; Arai, K.

2009-01-01

We present a method for calculating scattering phase shifts which utilizes continuum-discretized states obtained in a bound-state type calculation. The wrong asymptotic behavior of the discretized state is remedied by means of the Green's function formalism. Test examples confirm the accuracy of the method. The α+n scattering is described using realistic nucleon-nucleon potentials. The 3/2 - and 1/2 - phase shifts obtained in a single-channel calculation are too small in comparison with experiment. The 1/2 + phase shifts are in reasonable agreement with experiment, and gain contributions both from the tensor and central components of the nucleon-nucleon potential.

A new interpretation of SAXS peaks in sulfonated poly(ether ether ketone) (sPEEK) membranes for fuel cells.

Science.gov (United States)

Mendil-Jakani, H; Zamanillo Lopez, I; Legrand, P M; Mareau, V H; Gonon, L

2014-06-21

The structure of a commercial sulfonated poly(ether ether ketone) (sPEEK) membrane was analyzed by Small-Angle X-Ray Scattering (SAXS) for different water uptakes obtained after immersion in liquid water at various temperatures. For low membrane swelling, the SAXS profile displays only a wide-angle peak in the 0.2-0.3 Å(-1) region. As the membrane swells, two supplementary correlation peaks arise and shift towards small angles, which are the signature of a structural evolution of the membrane, whereas the wide angle peak remains stable. The SAXS spectra of sPEEK membranes can thus display three correlation peaks simultaneously. Therefore we propose a new interpretation of these SAXS spectra which conclude that the two small angle peaks are attributed to the so-called matrix and ionomer peaks and the wide-angle peak is ascribed to the mean separation distance between sulfonic acid groups grafted onto the polymer backbone. This peak attribution implies that the sPEEK nano-phase separation is triggered by an immersion in hot water (ionomer peak apparition). Our new peak attribution was confirmed by studying the impact of temperature, electron density contrast and ionic exchange capacity.

Quantitative optical extinction-based parametric method for sizing a single core-shell Ag-Ag{sub 2}O nanoparticle

Energy Technology Data Exchange (ETDEWEB)

Santillan, J M J; Scaffardi, L B; Schinca, D C, E-mail: lucias@ciop.unlp.edu.ar [Centro de Investigaciones Opticas (CIOp), (CONICET La Plata-CIC) (Argentina)

2011-03-16

This paper develops a parametric method for determining the core radius and shell thickness in small silver-silver-oxide core-shell nanoparticles (Nps) based on single particle optical extinction spectroscopy. The method is based on the study of the relationship between plasmon peak wavelength, full width at half maximum (FWHM) and contrast of the extinction spectra as a function of core radius and shell thickness. This study reveals that plasmon peak wavelength is strongly dependent on shell thickness, whereas FWHM and contrast depend on both variables. These characteristics may be used for establishing an easy and fast stepwise procedure to size core-shell NPs from single particle absorption spectrum. The importance of the method lies in the possibility of monitoring the growth of the silver-oxide layer around small spherical silver Nps in real time. Using the electrostatic approximation of Mie theory, core-shell single particle extinction spectra were calculated for a silver particle's core size smaller than about 20 nm and different thicknesses of silver oxide around it. Analysis of the obtained curves shows a very particular characteristic of the plasmon peak of small silver-silver-oxide Nps, expressed in the fact that its position is strongly dependent on oxide thickness and weakly dependent on the core radius. Even a very thin oxide layer shifts the plasmon peak noticeably, enabling plasmon tuning with appropriate shell thickness. This characteristic, together with the behaviour of FWHM and contrast of the extinction spectra can be combined into a parametric method for sizing both core and shell of single silver Nps in a medium using only optical information. In turn, shell thickness can be related to oxygen content in the Np's surrounding media. The method proposed is applied to size silver Nps from single particle extinction spectrum. The results are compared with full optical spectrum fitting using the electrostatic approximation in Mie theory

Evaluating the traditional day and night shift in an acute care surgery fellowship: Is the swing shift a better choice?

Science.gov (United States)

Chestovich, Paul J; McNicoll, Christopher F; Ingalls, Nichole K; Kuhls, Deborah A; Fraser, Douglas R; Morrissey, Shawna L; Fildes, John J

2018-01-01

Fellowship trainees in acute care surgery require experience in the management of complex and operative trauma cases. Trauma center staffing usually follows standard 12-hour or 24-hour shifts, with resident and fellow trainees following a similar schedule. Although trauma admissions can be generally unpredictable, we analyzed temporal trends of trauma patient arrival times to determine the best time frame to maximize trainee experience during each day. We reviewed 10 years (2007-2016) of trauma registry data for blunt and penetrating trauma activations. Hourly volumetric trends were observed, and three specific events were chosen for detailed analysis: (1) trauma activation with Injury Severity Score (ISS) greater than 15, (2) laparotomy for trauma, and (3) thoracotomy for trauma. A retrospective shift log was created, which included day (7:00 AM to 7:00 PM), night (7:00 PM to 7:00 AM), and swing (noon to midnight) shifts. A swing shift was chosen because it captures the peak volume for all three events. Means and 95% confidence intervals were calculated, and comparisons were made between shifts using the Wilcoxon matched-pairs signed rank test with Bonferroni correction, and p less than 0.05 considered significant. During the 10-year study period, 28,287 patients were treated at our trauma center. This included the evaluation and management of 7,874 patients with ISS greater than 15, performance of 1,766 laparotomies, and 392 thoracotomies for trauma. Swing shift was superior to both day and night shifts for ISS greater than 15 (p night shifts were superior to day shift for laparotomies (p day shift (p night shift (p = 0.031). Shifts with the highest yield of ISS greater than 15, laparotomies, and thoracotomies include night and swing shifts on Fridays and Saturdays. Projected experience of acute care surgery fellows in managing complex trauma patients increases with the integration of swing shifts into the schedule. Daily trauma volume follows a temporal pattern

Spectra of single-bubble sonoluminescence in water and glycerin-water mixtures

International Nuclear Information System (INIS)

Gaitan, D.F.; Atchley, A.A.; Lewia, S.D.; Carlson, J.T.; Maruyama, X.K.; Moran, M.; Sweider, D.

1996-01-01

A single gas bubble, acoustically levitated in a standing-wave field and oscillating under the action of that field, can emit pulses of blue-white light with duration less than 50 ps. Measurements of the spectrum of this picosecond sonoluminescence with a scanning monochrometer are reported for air bubbles levitated in water and in glycerin-water mixtures. While the spectrum has been reported previously by others for air bubbles in water, the spectrum for air bubbles in water-glycerin mixtures has not. Expected emission lines from glycerin were conspicuously absent, suggesting a different mechanism for light production in single-bubble sonoluminescence. Other conclusions are the spectrum for air bubbles in water is consistent with that previously reported, the radiated energy decreases as the glycerin concentration increases, and the peak of the spectrum appears to shift to longer wavelengths for the water-glycerin mixtures. copyright 1996 The American Physical Society

SEU-hardened design for shift register in CMOS APS

International Nuclear Information System (INIS)

Meng Liya; Liu Zedong; Hu Dajiang; Wang Qingxiang

2012-01-01

The inverter-based quasi-static shift register in CMOS APS, which is used in ionizing radiation environment, is susceptible to single event upset (SEU), thus affecting the CMOS active pixel sensor (APS) working. The analysis of the SEU for inverter-based quasi-static shift register concludes that the most sensitive node to single event transient (SET) exists in the input of inverter, and the threshold voltage and capacitance of input node of inverter determine the capability of anti-SEU. A new method was proposed, which replaced the inverter with Schmitt trigger in shift register. Because there is a hysteresis on voltage transfer characteristic of Schmitt trigger, there is high flip threshold, thus better capability of anti-SEU can be achieved. Simulation results show that the anti-SEU capability of Schmitt trigger is 10 times more than that of inverter. (authors)

A modified multiscale peak alignment method combined with trilinear decomposition to study the volatile/heat-labile components in Ligusticum chuanxiong Hort - Cyperus rotundus rhizomes by HS-SPME-GC/MS.

Science.gov (United States)

He, Min; Yan, Pan; Yang, Zhi-Yu; Zhang, Zhi-Min; Yang, Tian-Biao; Hong, Liang

2018-03-15

Head Space/Solid Phase Micro-Extraction (HS-SPME) coupled with Gas Chromatography/Mass Spectrometer (GC/MS) was used to determine the volatile/heat-labile components in Ligusticum chuanxiong Hort - Cyperus rotundus rhizomes. Facing co-eluting peaks in k samples, a trilinear structure was reconstructed to obtain the second-order advantage. The retention time (RT) shift with multi-channel detection signals for different samples has been vital in maintaining the trilinear structure, thus a modified multiscale peak alignment (mMSPA) method was proposed in this paper. The peak position and peak width of representative ion profile were firstly detected by mMSPA using Continuous Wavelet Transform with Haar wavelet as the mother wavelet (Haar CWT). Then, the raw shift was confirmed by Fast Fourier Transform (FFT) cross correlation calculation. To obtain the optimal shift, Haar CWT was again used to detect the subtle deviations and be amalgamated in calculation. Here, to ensure there is no peaks shape alternation, the alignment was performed in local domains of data matrices, and all data points in the peak zone were moved via linear interpolation in non-peak parts. Finally, chemical components of interest in Ligusticum chuanxiong Hort - Cyperus rotundus rhizomes were analyzed by HS-SPME-GCMS and mMSPA-alternating trilinear decomposition (ATLD) resolution. As a result, the concentration variation between herbs and their pharmaceutical products can provide a scientific basic for the quality standard establishment of traditional Chinese medicines. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of Accumulating Work Shifts on Performance-Based Fatigue Using Multiple Strength Measurements in Day and Night Shift Nurses and Aides.

Science.gov (United States)

Thompson, Brennan J; Stock, Matt S; Banuelas, Victoria K

2017-05-01

Objective This study aimed to examine the effects of accumulating nursing work on maximal and rapid strength characteristics in female nurses and compare these effects in day versus night shift workers. Background Nurses exhibit among the highest nonfatal injury rates of all occupations, which may be a consequence of long, cumulative work shift schedules. Fatigue may accumulate across multiple shifts and lead to performance impairments, which in turn may be linked to injury risks. Method Thirty-seven nurses and aides performed isometric strength-based performance testing of three muscle groups, including the knee extensors, knee flexors, and wrist flexors (hand grip), as well as countermovement jumps, at baseline and following exposure to three 12-hour work shifts in a four-day period. Variables included peak torque (PT) and rate of torque development (RTD) from isometric strength testing and jump height and power output. Results The rigorous work period resulted in significant decreases (-7.2% to -19.2%) in a large majority (8/9) of the isometric strength-based measurements. No differences were noted for the day versus night shift workers except for the RTD at 200 millisecond variable, for which the night shift had greater work-induced decreases than the day shift workers. No changes were observed for jump height or power output. Conclusions A compressed nursing work schedule resulted in decreases in strength-based performance abilities, being indicative of performance fatigue. Application Compressed work schedules involving long shifts lead to functional declines in nurse performance capacities that may pose risks for both the nurse and patient quality of care. Fatigue management plans are needed to monitor and regulate increased levels of fatigue.

Performance of single-junction and dual-junction InGaP/GaAs solar cells under low concentration ratios

International Nuclear Information System (INIS)

Khan, Aurangzeb; Yamaguchi, Masafumi; Takamoto, Tatsuya

2004-01-01

A study of the performance of single-junction InGaP/GaAs and dual-junction InGaP/GaAs tandem cells under low concentration ratios (up to 15 suns), before and after 1 MeV electron irradiation is presented. Analysis of the tunnel junction parameters under different concentrated light illuminations reveals that the peak current (J P ) and valley current (J V ) densities should be greater than the short-circuit current density (J sc ) for better performance. The tunnel junction behavior against light intensity improved after irradiation. This led to the suggestion that the peak current density (J P ) and valley current density (J V ) of the tunnel junction were enhanced after irradiation or the peak current was shifted to higher concentration. The recovery of the radiation damage under concentrated light illumination conditions suggests that the performance of the InGaP/GaAs tandem solar cell can be enhanced even under low concentration ratios

Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

KAUST Repository

Colas, Florent; Cottat, Maximilien; Gillibert, Raymond; Guillot, Nicolas; Djaker, Nadia; Lidgi-Guigui, Nathalie; Toury, Timothé e; Barchiesi, Dominique; Toma, Andrea; Di Fabrizio, Enzo M.; Gucciardi, Pietro Giuseppe; de la Chapelle, Marc Lamy

2016-01-01

Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

KAUST Repository

Colas, Florent

2016-06-06

Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

Influence of pure dephasing on emission spectra from single photon sources

DEFF Research Database (Denmark)

Næsby Rasmussen, Andreas; Skovgård, Troels Suhr; Kristensen, Philip Trøst

2008-01-01

We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate the char......We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate...

Conductivity peak, relaxation dynamics, and superconducting gap of YBa2Cu3O7 studied by terahertz and femtosecond optical spectroscopies

International Nuclear Information System (INIS)

Frenkel, A.; Gao, F.; Liu, Y.; Whitaker, J.F.; Uher, C.; Hou, S.Y.; Phillips, J.M.

1996-01-01

Recent measurements at microwave, terahertz (THz), and infrared frequencies have revealed a peak in σ 1 below T c . Based on our THz measurements, which were performed on high quality, single crystal films of YBCO (900 and 500 A), we have found that σ 1 features a peak which increases in amplitude and shifts to lower temperatures as frequency changes from 1.2 to 0.4 THz. Although the quasiparticle relaxation time extracted from these results using the two-fluid Drude model exhibits an enhancement below T c , the analysis may not be adequate to account for the strong frequency dependence of the conductivity peak by the competition between the drop in scattering rate and the decreasing normal fluid density with temperature. On the contrary, we were able to account for the frequency dependent σ 1 by fitting with Mattis-Bardeen theory (modified to include scattering) using a slower average rate of increase of the anisotropic gap than for the BCS case as temperature decreases below T c . This is consistent with the higher normal fluid density (higher than Gorter-Casimir values) from the two-fluid model interpretation of our THz results. Thus, we have found evidence of BCS coherence factors in a high-T c superconductor with a slower than BCS gap increase below T c . We have discussed the role of coherence factors to account for the presence of the conductivity peak and the absence of the peak in NMR relaxation rate. Furthermore, we have presented a model for the quasiparticle relaxation time measured by the femtosecond pump-probe spectroscopy. This model allowed us to find a fit to the temperature-dependent energy gap function which is also consistent with the slower gap increase below T c

Effect of 1,6-hexamethylene diisocyanate exposure on peak flowmetry in automobile paint shop workers in Iran.

Science.gov (United States)

Pourabedian, Siyamak; Barkhordari, Abdullah; Habibi, Ehsanallah; Rismanchiyan, Masoud; Zare, Mohsen

2010-06-01

The aim of this study was to investigate the effects of occupational exposure to 1,6-hexamethylene diisocyanate (HDI) on peak flowmetry in automobile body paint shop workers in Iran. We studied a population of 43 car painters exposed to HDI at their workplaces. Peak expiratory flow was tested for one working week, from the start to the end of each shift. Air was sampled and HDI analysed in parallel, according to the OSHA 42 method. Daily and weekly HDI exposure averages were (0.42+/-0.1) mg m(-3) and (0.13+/-0.05) mg m(-3), respectively. On painting days, 72 % of workers showed more than a 10 % variation in peak expiratory flow. Inhalation exposure exceeded the threshold limit value (TLV) ten times over. This strongly suggests that HDI affected the peak flowmetry in the studied workers.

Auxotonic to isometric contraction transitioning in a beating heart causes myosin step-size to down shift.

Directory of Open Access Journals (Sweden)

Thomas P Burghardt

Full Text Available Myosin motors in cardiac ventriculum convert ATP free energy to the work of moving blood volume under pressure. The actin bound motor cyclically rotates its lever-arm/light-chain complex linking motor generated torque to the myosin filament backbone and translating actin against resisting force. Previous research showed that the unloaded in vitro motor is described with high precision by single molecule mechanical characteristics including unitary step-sizes of approximately 3, 5, and 8 nm and their relative step-frequencies of approximately 13, 50, and 37%. The 3 and 8 nm unitary step-sizes are dependent on myosin essential light chain (ELC N-terminus actin binding. Step-size and step-frequency quantitation specifies in vitro motor function including duty-ratio, power, and strain sensitivity metrics. In vivo, motors integrated into the muscle sarcomere form the more complex and hierarchically functioning muscle machine. The goal of the research reported here is to measure single myosin step-size and step-frequency in vivo to assess how tissue integration impacts motor function. A photoactivatable GFP tags the ventriculum myosin lever-arm/light-chain complex in the beating heart of a live zebrafish embryo. Detected single GFP emission reports time-resolved myosin lever-arm orientation interpreted as step-size and step-frequency providing single myosin mechanical characteristics over the active cycle. Following step-frequency of cardiac ventriculum myosin transitioning from low to high force in relaxed to auxotonic to isometric contraction phases indicates that the imposition of resisting force during contraction causes the motor to down-shift to the 3 nm step-size accounting for >80% of all the steps in the near-isometric phase. At peak force, the ATP initiated actomyosin dissociation is the predominant strain inhibited transition in the native myosin contraction cycle. The proposed model for motor down-shifting and strain sensing involves ELC N

Improvement of the XANAM System and Acquisition of a Peak Signal with a High S/N ratio

International Nuclear Information System (INIS)

Suzuki, S; Nakamura, M; Kinoshita, K; Koike, Y; Fujikawa, K; Matsudaira, N; Chun, W-J; Nomura, M; Asakura, K

2007-01-01

We have made remarkable progress in detecting X-ray-induced frequency shift signals, which will promote development of a chemically sensitive NC-AFM. A highperformance controller provides a tenfold higher signal to noise ratio than that previously reported. We confirmed that the frequency shift or complementary Z-feedback signal dependence on X-ray energy has a peak. An important feature of the signal is that it does not follow the absorption spectrum of a surface element. These new findings are important to elucidate this novel X-ray-induced phenomenon

Finding Multiple Peaks Signal in Fast Beam Conditions Monitor (BCM1F)

CERN Document Server

Bin Ab Maalek, Abu Ubaidah Amir; CERN. Geneva. EP Department

2017-01-01

Fast Beam Conditions Monitor (BCM1F) is diamond and silicon sensors based luminometer of CMS detector. The methods of finding multiple peaks signal in BCM1F is shown. Multiple peaks signal found at signal with width between 60 ns - 300 ns. Double peaks are counted as single hit in the constant threshold analysis and leads to underestimation in the luminosity. Therefore it should be estimated for different filling schemes and sensor types. The percentage of long width pulse in different sensor for different fill are calculated. About 30 \\% long width pulse found in sCVD sensor, 12 \\% in pCVD and no more than 1 \\% for silicon sensor.

Online short-term heat load forecasting for single family houses

DEFF Research Database (Denmark)

Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

2013-01-01

. Every hour the hourly heat load for each house the following two days is forecasted. The forecast models are adaptive linear time-series models and the climate inputs used are: ambient temperature, global radiation, and wind speed. A computationally efficient recursive least squares scheme is used......This paper presents a method for forecasting the load for heating in a single-family house. Both space and hot tap water heating are forecasted. The forecasting model is built using data from sixteen houses in Sønderborg, Denmark, combined with local climate measurements and weather forecasts...... variations in the heat load signal (predominant only for some houses), peaks presumably from showers, shifts in resident behavior, and uncertainty of the weather forecasts for longer horizons, especially for the solar radiation....

Computation of distribution of minimum resolution for log-normal distribution of chromatographic peak heights.

Science.gov (United States)

Davis, Joe M

2011-10-28

General equations are derived for the distribution of minimum resolution between two chromatographic peaks, when peak heights in a multi-component chromatogram follow a continuous statistical distribution. The derivation draws on published theory by relating the area under the distribution of minimum resolution to the area under the distribution of the ratio of peak heights, which in turn is derived from the peak-height distribution. Two procedures are proposed for the equations' numerical solution. The procedures are applied to the log-normal distribution, which recently was reported to describe the distribution of component concentrations in three complex natural mixtures. For published statistical parameters of these mixtures, the distribution of minimum resolution is similar to that for the commonly assumed exponential distribution of peak heights used in statistical-overlap theory. However, these two distributions of minimum resolution can differ markedly, depending on the scale parameter of the log-normal distribution. Theory for the computation of the distribution of minimum resolution is extended to other cases of interest. With the log-normal distribution of peak heights as an example, the distribution of minimum resolution is computed when small peaks are lost due to noise or detection limits, and when the height of at least one peak is less than an upper limit. The distribution of minimum resolution shifts slightly to lower resolution values in the first case and to markedly larger resolution values in the second one. The theory and numerical procedure are confirmed by Monte Carlo simulation. Copyright © 2011 Elsevier B.V. All rights reserved.

Self-similar bumps and wiggles: Isolating the evolution of the BAO peak with power-law initial conditions

International Nuclear Information System (INIS)

Orban, Chris; Weinberg, David H.

2011-01-01

Motivated by cosmological surveys that demand accurate theoretical modeling of the baryon acoustic oscillation (BAO) feature in galaxy clustering, we analyze N-body simulations in which a BAO-like Gaussian bump modulates the linear theory correlation function ξ L (r)=(r 0 /r) n+3 of an underlying self-similar model with initial power spectrum P(k)=Ak n . These simulations test physical and analytic descriptions of BAO evolution far beyond the range of most studies, since we consider a range of underlying power spectra (n=-0.5, -1, -1.5) and evolve simulations to large effective correlation amplitudes (equivalent to σ 8 =4-12 for r bao =100h -1 Mpc). In all cases, nonlinear evolution flattens and broadens the BAO bump in ξ(r) while approximately preserving its area. This evolution resembles a diffusion process in which the bump width σ bao is the quadrature sum of the linear theory width and a length proportional to the rms relative displacement Σ pair (r bao ) of particle pairs separated by r bao . For n=-0.5 and n=-1, we find no detectable shift of the location of the BAO peak, but the peak in the n=-1.5 model shifts steadily to smaller scales, following r peak /r bao =1-1.08(r 0 /r bao ) 1.5 . The perturbation theory scheme of McDonald (2007) [P. McDonald, Phys. Rev. D 75, 043514 (2007).] and, to a lesser extent, standard 1-loop perturbation theory are fairly successful at explaining the nonlinear evolution of the Fourier power spectrum of our models. Analytic models also explain why the ξ(r) peak shifts much more for n=-1.5 than for n≥-1, though no ab initio model we have examined reproduces all of our numerical results. Simulations with L box =10r bao and L box =20r bao yield consistent results for ξ(r) at the BAO scale, provided one corrects for the integral constraint imposed by the uniform density box.

Evidence of oxygen vacancy and possible intermediate gap state in layered α-MoO{sub 3} single-crystal nanobelts

Energy Technology Data Exchange (ETDEWEB)

Chen, C.Z., E-mail: tcccz@shu.edu.cn; Li, Y.; Tang, X.D.

2016-01-15

Multilayered meso-structured MoO{sub 3} nanobelts have been synthesized by thermally oxidizing a molybdenum chip in a reduced oxygen atmosphere, with a view to disclosing the existence of oxygen vacancy and understanding the mechanism behind the influence of oxygen vacancy on the electronic structure of molybdenum oxides. Based on the measurements from X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM), it is found that the as-grown sample is single-crystal α-MoO{sub 3} with a (001) preferred orientation, which shows an irregular belt-like morphology being composed of some ~20 nm single-crystal thin layers. The present sample includes a lot of oxygen vacancies in the lattice, as evidenced by the considerably reduced coordination number of the central Mo atoms from X-ray absorption spectra (XAS) as well as the red shift of the main Raman peaks. The existence of the oxygen vacancies are further tested by the photoluminescence (PL) results as the main emission peak shows an obvious red shift with the corresponding optical band gap reduced to 2.3 eV. Very importantly, an extra emission positioned at 738 nm (1.68 eV) is believed to originate from the recombination of the electrons from the intermediate band (IB) to the valence band (VB), and the formation of the IB in the gap is also caused by oxygen-ion vacancies.

Observables in topological Yang-Mills theories with extended shift supersymmetry

Energy Technology Data Exchange (ETDEWEB)

Constantinidis, Clisthenis P; Piguet, Olivier [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil); Spalenza, Wesley [Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste (Italy); Centro Brasileiro de Pesquisas Fsicas (CBPF), Rio de Janeiro (Brazil)

2006-01-01

We present a complete classification, at the classical level, of the observables of topological Yang-Mills theories with an extended shift supersymmetry of N generators, in any space-time dimension. The observables are defined as the Yang-Mills BRST cohomology classes of shift supersymmetry invariants. These cohomology classes turn out to be solutions of an N-extension of Witten's equivariant cohomology. This work generalizes results known in the case of shift supersymmetry with a single generator. (orig.)

Control of the Rendition Wavelength Shifts of Color Lippmann Holograms Recorded in Single-layer panchromatic Silver-halide Emulsion

Institute of Scientific and Technical Information of China (English)

ZHU Jianhua; GUO Lurong; LI Zuoyou; LIU Zhenqing

2000-01-01

Russian PFG-03C panchromatic ultra-high resolution silver-halide emulsion is regarded as the most successful material for the fabrication of color reflection holograms. But the lack of established and reliable processing sequences prevents its practical applications in business and everyday life. Though much attention is drawn upon the processing of PFG-03C color reflection holograms, the color desaturation is still a problem. The article describes the new processing of color holograms recorded in PFG- 03C plates which is demonstrated experimentally to have the capacity of controlling the rendition wavelength shifts and improving the color desaturation effectively. The rendition spectra of Red-Green-Blue (R. G. B. ) single-line reflection holographic gratings, and the color reflection hologram as well, are given in this paper.

Acquisition of peak responding: what is learned?

Science.gov (United States)

Balci, Fuat; Gallistel, Charles R; Allen, Brian D; Frank, Krystal M; Gibson, Jacqueline M; Brunner, Daniela

2009-01-01

We investigated how the common measures of timing performance behaved in the course of training on the peak procedure in C3H mice. Following fixed interval (FI) pre-training, mice received 16 days of training in the peak procedure. The peak time and spread were derived from the average response rates while the start and stop times and their relative variability were derived from a single-trial analysis. Temporal precision (response spread) appeared to improve in the course of training. This apparent improvement in precision was, however, an averaging artifact; it was mediated by the staggered appearance of timed stops, rather than by the delayed occurrence of start times. Trial-by-trial analysis of the stop times for individual subjects revealed that stops appeared abruptly after three to five sessions and their timing did not change as training was prolonged. Start times and the precision of start and stop times were generally stable throughout training. Our results show that subjects do not gradually learn to time their start or stop of responding. Instead, they learn the duration of the FI, with robust temporal control over the start of the response; the control over the stop of response appears abruptly later.

Light emission ranging from blue to red from a series of Iguana/GaN single quantum wells

Energy Technology Data Exchange (ETDEWEB)

Martin, R.W. [Department of Physics, University of Strathclyde, Glasgow (United Kingdom)]. E-mail: r.w.martin@strath.ac.uk; Edwards, P.R.; Pecharroman-Gallego, R.; O' Donnell, K.P. [Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Liu, C.; Deatcher, C.J.; Watson, I.M. [Institute of Photonics, University of Strathclyde, Glasgow (United Kingdom)

2002-04-07

In this paper, we describe the growth and characterization of InGaN single quantum wells with emission peaks in the blue, green, amber and red spectral regions, grown by metal-organic vapour phase epitaxy. Starting from the growth of a blue-emitting (peak {approx}430 nm) InGaN quantum well at 860 deg. C the InGaN growth temperature was progressively reduced. The photoluminescence peak wavelength, measured at low temperature, shifts through the green and orange spectral regions and reaches 670 nm for an InGaN growth temperature of 760 deg. C. This corresponds to an energy lower than the currently accepted band-gap of the binary compound, InN. Spectral characteristics of the luminescence peaks will be discussed, including an analysis of the phonon-assisted contribution. Low energy secondary ion mass spectrometry analysis provides information on the indium content and thickness of the 'blue' and 'red' quantum wells. The results are combined to discuss the origin of the 'sub-band-gap' luminescence in terms of the combined influence of InN-GaN segregation and the effect of intense piezoelectric fields. (author)

Light emission ranging from blue to red from a series of Iguana/GaN single quantum wells

International Nuclear Information System (INIS)

Martin, R.W.; Edwards, P.R.; Pecharroman-Gallego, R.; O'Donnell, K.P.; Liu, C.; Deatcher, C.J.; Watson, I.M.

2002-01-01

In this paper, we describe the growth and characterization of InGaN single quantum wells with emission peaks in the blue, green, amber and red spectral regions, grown by metal-organic vapour phase epitaxy. Starting from the growth of a blue-emitting (peak ∼430 nm) InGaN quantum well at 860 deg. C the InGaN growth temperature was progressively reduced. The photoluminescence peak wavelength, measured at low temperature, shifts through the green and orange spectral regions and reaches 670 nm for an InGaN growth temperature of 760 deg. C. This corresponds to an energy lower than the currently accepted band-gap of the binary compound, InN. Spectral characteristics of the luminescence peaks will be discussed, including an analysis of the phonon-assisted contribution. Low energy secondary ion mass spectrometry analysis provides information on the indium content and thickness of the 'blue' and 'red' quantum wells. The results are combined to discuss the origin of the 'sub-band-gap' luminescence in terms of the combined influence of InN-GaN segregation and the effect of intense piezoelectric fields. (author)

Analysis of user equilibrium for staggered shifts in a single-entry traffic corridor with no late arrivals

Science.gov (United States)

Li, Chuan-Yao; Huang, Hai-Jun; Tang, Tie-Qiao

2017-05-01

In this paper, we investigate the effects of staggered shifts on the user equilibrium (UE) state in a single-entry traffic corridor with no late arrivals from the analytical and numerical perspective. The LWR (Lighthill-Whitham-Richards) model and the Greenshields' velocity-density function are used to describe the dynamic properties of traffic flow. Propositions for the properties of flow patterns in UE, and the quasi-analytic solutions for three possible situations in UE are deduced. Numerical tests are carried out to testify the analytical results, where the three-dimensional evolution diagram of traffic flow illustrates that shock and rarefaction wave exist in UE and the space-time diagram indicates that UE solutions satisfy the propagation properties of traffic flow. In addition, the cost curves show that the UE solutions satisfy the UE trip-timing condition.

Dielectric behavior and phase transition in [111]-oriented PIN–PMN–PT single crystals under dc bias

Directory of Open Access Journals (Sweden)

Yuhui Wan

2014-01-01

Full Text Available Temperature and electric field dependences of the dielectric behavior and phase transition for [111]-oriented 0.23PIN–0.52PMN–0.25PT (PIN-PMN–0.25PT and 0.24PIN–0.43PMN–0.33PT (PIN–PMN–0.33PT single crystals were investigated over a temperature range from -100°C to 250°C using field-heating (FH dielectric measurements. The transition phenomenon from ferroelectric microdomain to macrodomain was found in rhombohedra (R phase region in the single crystals under dc bias. This transition temperature Tf of micro-to-macrodomain is sensitive to dc bias and move quickly to lower temperature with increasing dc bias. The phase transition temperatures in the two single crystals shift toward high temperature and the dielectric permittivities at the phase transition temperature decrease with increasing dc bias. Especially, the phase transition peaks are gradually broad in PIN–PMN–0.33PT single crystal with the increasing dc bias. Effects of dc bias on the dielectric behavior and phase transition in PIN–PMN–PT single crystals are discussed.

Deep tissue optical imaging of upconverting nanoparticles enabled by exploiting higher intrinsic quantum yield through use of millisecond single pulse excitation with high peak power

DEFF Research Database (Denmark)

Liu, Haichun; Xu, Can T.; Dumlupinar, Gökhan

2013-01-01

We have accomplished deep tissue optical imaging of upconverting nanoparticles at 800 nm, using millisecond single pulse excitation with high peak power. This is achieved by carefully choosing the pulse parameters, derived from time-resolved rate-equation analysis, which result in higher intrinsic...... quantum yield that is utilized by upconverting nanoparticles for generating this near infrared upconversion emission. The pulsed excitation approach thus promises previously unreachable imaging depths and shorter data acquisition times compared with continuous wave excitation, while simultaneously keeping...... therapy and remote activation of biomolecules in deep tissues....

Communication: Systematic shifts of the lowest unoccupied molecular orbital peak in x-ray absorption for a series of 3d metal porphyrins

DEFF Research Database (Denmark)

García Lastra, Juan Maria; Cook, P. L.; Himpsel, F. J.

2010-01-01

Porphyrins are widely used as dye molecules in solar cells. Knowing the energies of their frontier orbitals is crucial for optimizing the energy level structure of solar cells. We use near edge x-ray absorption fine structure (NEXAFS) spectroscopy to obtain the energy of the lowest unoccupied...... molecular orbital (LUMO) with respect to the N-1s core level of the molecule. A systematic energy shift of the N-1s to LUMO transition is found along a series of 3d metal octaethylporphyrins and explained by density functional theory. It is mainly due to a shift of the N-1s level rather than a shift...

Solid state cathodoluminescence and the properties of its two emission peaks

International Nuclear Information System (INIS)

Xu Xurong

2007-01-01

We discovered solid state cathodoluminescence (SSCL). For its identification we excluded all artifacts, carried out its cross proof and studied its generality. Its spectrum is characterized by the appearance of short wavelength peak when the applied voltage is increased. Three voltage ranges are distinguished, in the lower voltage range we have the long wavelength emission, in the middle range we have both long and short wavelength emissions, and in the higher voltage range we have only the short wavelength emission. The mechanism of this spectral shift lies in the electrical field ionization of excitons. This effect initiates the applicability of band model besides molecular excitons theory. The temporal behaviors of both peaks in SSCL are studied with a method of estimating lifetime by means of frequency dependence on intensity. The lifetime of short wavelength emission is found to be 5 ms and that of long wavelength emission is less than 0.05 ms

Chemical Shift Imaging (CSI) by precise object displacement

OpenAIRE

Leclerc, Sebastien; Trausch, Gregory; Cordier, Benoit; Grandclaude, Denis; Retournard, Alain; Fraissard, Jacques; Canet, Daniel

2006-01-01

International audience; A mechanical device (NMR lift) has been built for displacing vertically an object (typically a NMR sample tube) inside the NMR probe with an accuracy of 1 Μm. A series of single pulse experiments are performed for incremented vertical positions of the sample. With a sufficiently spatially selective rf field, one obtains chemical shift information along the displacement direction (one dimensional Chemical Shift Imaging – CSI). Knowing the vertical radio-frequency (rf) f...

An analysis of China's CO2 emission peaking target and pathways

Directory of Open Access Journals (Sweden)

Jian-Kun He

2014-12-01

Full Text Available China has set the goal for its CO2 emissions to peak around 2030, which is not only a strategic decision coordinating domestic sustainable development and global climate change mitigation but also an overarching target and a key point of action for China's resource conservation, environmental protection, shift in economic development patterns, and CO2 emission reduction to avoid climate change. The development stage where China maps out the CO2 emission peak target is earlier than that of the developed countries. It is a necessity that the non-fossil energy supplies be able to meet all the increased energy demand for achieving CO2 emission peaking. Given that China's potential GDP annual increasing rate will be more than 4%, and China's total energy demand will continue to increase by approximately 1.0%–1.5% annually around 2030, new and renewable energies will need to increase by 6%–8% annually to meet the desired CO2 emission peak. The share of new and renewable energies in China's total primary energy supply will be approximately 20% by 2030. At that time, the energy consumption elasticity will decrease to around 0.3, and the annual decrease in the rate of CO2 intensity will also be higher than 4% to ensure the sustained growth of GDP. To achieve the CO2 emission peaking target and substantially promote the low-carbon development transformation, China needs to actively promote an energy production and consumption revolution, the innovation of advanced energy technologies, the reform of the energy regulatory system and pricing mechanism, and especially the construction of a national carbon emission cap and trade system.

Peaking for optimal performance: Research limitations and future directions.

Science.gov (United States)

Pyne, David B; Mujika, Iñigo; Reilly, Thomas

2009-02-01

A key element of the physical preparation of athletes is the taper period in the weeks immediately preceding competition. Existing research has defined the taper, identified various forms used in contemporary sport, and examined the prescription of training volume, load, intensity, duration, and type (progressive or step). Current limitations include: the lack of studies on team, combative, racquet, and precision (target) sports; the relatively small number of randomized controlled trials; the narrow focus on a single competition (single peak) compared with multiple peaking for weekly, multi-day or multiple events; and limited understanding of the physiological, neuromuscular, and biomechanical basis of the taper. Future research should address these limitations, together with the influence of prior training on optimal tapering strategies, and the interactions between the taper and long-haul travel, heat, and altitude. Practitioners seek information on how to prescribe tapers from season to season during an athlete's career, or a team's progression through a domestic league season, or multi-year Olympic or World Cup cycle. Practical guidelines for planning effective tapers for the Vancouver 2010 and London 2012 Olympics will evolve from both experimental investigations and modelling of successful tapers currently employed in a wide range of sports.

Elaboration and characterization of a KCl single crystal doped with nanocrystals of a Sb2O3 semiconductor

International Nuclear Information System (INIS)

Bouhdjer, L.; Addala, S.; Halimi, O.; Boudine, B.; Sebais, M.; Chala, A.

2013-01-01

Undoped and doped KCl single crystals have been successfully elaborated via the Czochralski (Cz) method. The effects of dopant Sb 2 O 3 nanocrystals on structural and optical properties were investigated by a number of techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX) analysis, UV-visible and photoluminescence (PL) spectrophotometers. An XRD pattern of KCl:Sb 2 O 3 reveals that the Sb 2 O 3 nanocrystals are in the well-crystalline orthorhombic phase. The broadening of diffraction peaks indicated the presence of a Sb 2 O 3 semiconductor in the nanometer size regime. The shift of absorption and PL peaks is observed near 334 nm and 360 nm respectively due to the quantum confinement effect in Sb 2 O 3 nanocrystals. Particle sizes calculated from XRD studies agree fairly well with those estimated from optical studies. An SEM image of the surface KCl:Sb 2 O 3 single crystal shows large quasi-spherical of Sb 2 O 3 crystallites scattered on the surface. The elemental analysis from EDAX demonstrates that the KCl:Sb 2 O 3 single crystal is slightly rich in oxygen and a source of excessive quantities of oxygen is discussed. (semiconductor materials)

Using 1H and 13C NMR chemical shifts to determine cyclic peptide conformations: a combined molecular dynamics and quantum mechanics approach.

Science.gov (United States)

Nguyen, Q Nhu N; Schwochert, Joshua; Tantillo, Dean J; Lokey, R Scott

2018-05-10

Solving conformations of cyclic peptides can provide insight into structure-activity and structure-property relationships, which can help in the design of compounds with improved bioactivity and/or ADME characteristics. The most common approaches for determining the structures of cyclic peptides are based on NMR-derived distance restraints obtained from NOESY or ROESY cross-peak intensities, and 3J-based dihedral restraints using the Karplus relationship. Unfortunately, these observables are often too weak, sparse, or degenerate to provide unequivocal, high-confidence solution structures, prompting us to investigate an alternative approach that relies only on 1H and 13C chemical shifts as experimental observables. This method, which we call conformational analysis from NMR and density-functional prediction of low-energy ensembles (CANDLE), uses molecular dynamics (MD) simulations to generate conformer families and density functional theory (DFT) calculations to predict their 1H and 13C chemical shifts. Iterative conformer searches and DFT energy calculations on a cyclic peptide-peptoid hybrid yielded Boltzmann ensembles whose predicted chemical shifts matched the experimental values better than any single conformer. For these compounds, CANDLE outperformed the classic NOE- and 3J-coupling-based approach by disambiguating similar β-turn types and also enabled the structural elucidation of the minor conformer. Through the use of chemical shifts, in conjunction with DFT and MD calculations, CANDLE can help illuminate conformational ensembles of cyclic peptides in solution.

Enhanced light scattering of the forbidden longitudinal optical phonon mode studied by micro-Raman spectroscopy on single InN nanowires

International Nuclear Information System (INIS)

Schaefer-Nolte, E O; Stoica, T; Gotschke, T; Limbach, F A; Gruetzmacher, D; Calarco, R; Sutter, E; Sutter, P

2010-01-01

In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E 2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

Enhanced Light Scattering of the Forbidden longitudinal Optical Phonon Mode Studied by Micro-Raman Spectroscopy on Single InN nanowires

International Nuclear Information System (INIS)

Sutter, E.; Schafer-Nolte, E.O.; Stoica, T.; Gotschke, T.; Limbach, F.A.; Sutter, P.; Grutzmacher, D.; Calarco, R.

2010-01-01

In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E2 phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

Enhanced light scattering of the forbidden longitudinal optical phonon mode studied by micro-Raman spectroscopy on single InN nanowires.

Science.gov (United States)

Schäfer-Nolte, E O; Stoica, T; Gotschke, T; Limbach, F A; Sutter, E; Sutter, P; Grützmacher, D; Calarco, R

2010-08-06

In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E(2) phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

Role of medial cortical, hippocampal and striatal interactions during cognitive set-shifting.

Science.gov (United States)

Graham, Steven; Phua, Elaine; Soon, Chun Siong; Oh, Tomasina; Au, Chris; Shuter, Borys; Wang, Shih-Chang; Yeh, Ing Berne

2009-05-01

To date, few studies have examined the functional connectivity of brain regions involved in complex executive function tasks, such as cognitive set-shifting. In this study, eighteen healthy volunteers performed a cognitive set-shifting task modified from the Wisconsin card sort test while undergoing functional magnetic resonance imaging. These modifications allowed better disambiguation between cognitive processes and revealed several novel findings: 1) peak activation in the caudate nuclei in the first instance of negative feedback signaling a shift in rule, 2) lowest caudate activation once the rule had been identified, 3) peak hippocampal activation once the identity of the rule had been established, and 4) decreased hippocampal activation during the generation of new rule candidates. This pattern of activation across cognitive set-shifting events suggests that the caudate nuclei play a role in response generation when the identity of the new rule is unknown. In contrast, the reciprocal pattern of hippocampal activation suggests that the hippocampi help consolidate knowledge about the correct stimulus-stimulus associations, associations that become inappropriate once the rule has changed. Functional connectivity analysis using Granger Causality Mapping revealed that caudate and hippocampal regions interacted indirectly via a circuit involving the medial orbitofrontal and posterior cingulate regions, which are known to bias attention towards stimuli based on expectations built up from task-related feedback. Taken together, the evidence suggests that these medial regions may mediate striato-hippocampal interactions and hence affect goal-directed attentional transitions from a response strategy based on stimulus-reward heuristics (caudate-dependent) to one based on stimulus-stimulus associations (hippocampus-dependent).

Peak Politics: Resource Scarcity and Libertarian Political Culture in the United States

Science.gov (United States)

Schneider-Mayerson, Matthew

My dissertation uses the "peak oil" movement as a lens to analyze the convergence of apocalyptic environmental thinking and libertarian political culture in the recent United States. The "peak oil" movement was a twenty-first century American social movement of Americans who came to believe that oil depletion and other environmental problems would lead to the imminent collapse of global industrial society. Dedicated adherents developed a rich subculture, primarily online, and prepared themselves for the "post-carbon" future by conserving energy, changing occupations, and even purchasing land. Drawing on surveys of over 1,500 participants, ethnographic research, discourse analysis of peak oil websites and literary analysis of subcultural fiction, my research reveals a group of mostly white, male, liberal Americans struggling with the perceived threat of economic, environmental and geopolitical decline while the country undergoes a broad shift in political culture: the continued rise of libertarian ideals, accelerated by the influence of Internet technology. I view this apocalyptic subculture in the context of petroleum dependence, eco-apocalyptic discourses, the environmental discourse of "limits to growth," white masculinity, climate change, and the influence of conservative individualism on American political culture.

Electricity Portfolio Management: Optimal Peak / Off-Peak Allocations

OpenAIRE

Huisman, Ronald; Mahieu, Ronald; Schlichter, Felix

2007-01-01

textabstractElectricity purchasers manage a portfolio of contracts in order to purchase the expected future electricity consumption profile of a company or a pool of clients. This paper proposes a mean-variance framework to address the concept of structuring the portfolio and focuses on how to allocate optimal positions in peak and off-peak forward contracts. It is shown that the optimal allocations are based on the difference in risk premiums per unit of day-ahead risk as a measure of relati...

Identification of a common single nucleotide polymorphism at the primer binding site of D2S1360 that causes heterozygote peak imbalance when using the Investigator HDplex Kit.

Science.gov (United States)

Inokuchi, Shota; Yamashita, Yasuhiro; Nishimura, Kazuma; Nakanishi, Hiroaki; Saito, Kazuyuki

2017-11-01

Phenomena known as null alleles and peak imbalance can occur because of mutations in the primer binding sites used for DNA typing. In these cases, an accurate statistical evaluation of DNA typing is difficult. The estimated likelihood ratio is incorrectly calculated because of the null allele and allele dropout caused by mutation-induced peak imbalance. Although a number of studies have attempted to uncover examples of these phenomena, few reports are available on the human identification kit manufactured by Qiagen. In this study, 196 Japanese individuals who were heterozygous at D2S1360 were genotyped using an Investigator HDplex Kit with optimal amounts of DNA. A peak imbalance was frequently observed at the D2S1360 locus. We performed a sequencing analysis of the area surrounding the D2S1360 repeat motif to identify the cause for peak imbalance. A point mutation (G>A transition) 136 nucleotides upstream from the D2S1360 repeat motif was discovered in a number of samples. The allele frequency of the mutation was 0.0566 in the Japanese population. Therefore, human identification or kinship testing using the Investigator HDplex Kit requires caution because of the higher frequency of single nucleotide polymorphisms at the primer binding site of D2S1360 locus in the Japanese population.

High-temperature superconducting shift registers operating at up to 100 GHz

International Nuclear Information System (INIS)

Martens, J.S.; Pance, A.; Char, K.

1994-01-01

Shift registers have been demonstrated in YBaCuO operating at 77 K using from 64 to over 1,000 junctions. These are some of the larger scale integrated circuits demonstrated to date using YBaCuO Josephson technology. The circuit is a modified rapid single flux quantum design in which a single trigger pulse causes a one bit shift of the entire word of 32--512 b in length. Two different junction technologies, electron-beam defined nanobridges and epitaxial edge junctions, have been used with parameter spreads ranging from 11% to 22%. Correct operation has been verified with low speed random word tests and circulating data tests while pseudo random bit sequence demonstrations are underway. A practical amount of time to shift between cells has been measured to be about 10 ps

Effects of marital status and shift work on family function among registered nurses.

Science.gov (United States)

Tai, Shu-Yu; Lin, Pei-Chen; Chen, Yao-Mei; Hung, Hsin-Chia; Pan, Chih-Hong; Pan, Shung-Mei; Lee, Chung-Yin; Huang, Chia-Tsuan; Wu, Ming-Tsang

2014-01-01

This study aims to assess the interactive effect of marital status and shift work on family function. A population-based sample of 1,438 nurses between the ages of 20-45 yr was recruited from Taiwan during the period from July 2005 to April 2006 using a mailed questionnaire. The self-administered questionnaire contained information about demographic data, work status, shift work schedule, and the Family APGAR (Adaptation, Partnership, Growth, Affection, and Resolve) Scale, to evaluate family function. Compared to day shift nurses, non-night and rotation shift nurses had 1.53- and 1.38-fold (95% CI=1.09-2.14 and 1.01-1.88) risk to have poor family function after adjusting for other covariates. Married nurses, by contrast, had a 0.44-fold (95% CI=0.29-0.66) risk to have poor family function compared to single nurses. In addition, married nurses who worked non-night or rotation shifts had a significantly higher percent of poor family function than those married nurses working day shifts; however, similar results were not replicated in single nurses. We concluded that shift work and marital status could influence family function.

Effects of Marital Status and Shift Work on Family Function among Registered Nurses

Science.gov (United States)

TAI, Shu-Yu; LIN, Pei-Chen; CHEN, Yao-Mei; HUNG, Hsin-Chia; PAN, Chih-Hong; PAN, Shung-Mei; LEE, Chung-Yin; HUANG, Chia-Tsuan; WU, Ming-Tsang

2014-01-01

This study aims to assess the interactive effect of marital status and shift work on family function. A population-based sample of 1,438 nurses between the ages of 20–45 yr was recruited from Taiwan during the period from July 2005 to April 2006 using a mailed questionnaire. The self-administered questionnaire contained information about demographic data, work status, shift work schedule, and the Family APGAR (Adaptation, Partnership, Growth, Affection, and Resolve) Scale, to evaluate family function. Compared to day shift nurses, non-night and rotation shift nurses had 1.53- and 1.38-fold (95% CI=1.09–2.14 and 1.01–1.88) risk to have poor family function after adjusting for other covariates. Married nurses, by contrast, had a 0.44-fold (95% CI=0.29–0.66) risk to have poor family function compared to single nurses. In addition, married nurses who worked non-night or rotation shifts had a significantly higher percent of poor family function than those married nurses working day shifts; however, similar results were not replicated in single nurses. We concluded that shift work and marital status could influence family function. PMID:24909112

A proposed wind shift model for the German reactor safety study

International Nuclear Information System (INIS)

Aldrich, D.C.; Bayer, A.; Schueckler, M.

1979-04-01

To account for hourly wind direction changes, a wind shift model has been proposed. Using hourly recorded wind speed and direction data, the model modifies the angular distribution of radionuclide concentrations calculated by a straightline model, and is intended to better represent the concentrations in areas close to the reactor where potential doses might exceed the threshold level for early fatalities. 115 weather sequences were used, both with and without the proposed wind shift model, to calculate probability distributions for early fatalities. The use of the proposed model results in a reduction of the mean and peak values of that distribution by 36% and 29%, respectively. (orig./HP) [de

Picosecond, single pulse electron linear accelerator

International Nuclear Information System (INIS)

Kikuchi, Riichi; Kawanishi, Masaharu

1979-01-01

The picosecond, single pulse electron linear accelerators, are described, which were installed in the Nuclear Engineering Laboratory of the University of Tokyo and in the Nuclear Radiation Laboratory of the Osaka University. The purpose of the picosecond, single pulse electron linear accelerators is to investigate the very short time reaction of the substances, into which gamma ray or electron beam enters. When the electrons in substances receive radiation energy, the electrons get high kinetic energy, and the energy and the electric charge shift, at last to the quasi-stable state. This transient state can be experimented with these special accelerators very accurately, during picoseconds, raising the accuracy of the time of incidence of radiation and also raising the accuracy of observation time. The outline of these picosecond, single pulse electron linear accelerators of the University of Tokyo and the Osaka University, including the history, the systems and components and the output beam characteristics, are explained. For example, the maximum energy 30 -- 35 MeV, the peak current 1 -- 8 n C, the pulse width 18 -- 40 ps, the pulse repetition rate 200 -- 720 pps, the energy spectrum 1 -- 1.8% and the output beam diameter 2 -- 5 mm are shown as the output beam characteristics of the accelerators in both universities. The investigations utilizing the picosecond single pulse electron linear accelerators, such as the investigation of short life excitation state by pulsed radiation, the dosimetry study of pulsed radiation, and the investigation of the transforming mechanism and the development of the transforming technology from picosecond, single pulse electron beam to X ray, vacuum ultraviolet ray and visual ray, are described. (Nakai, Y.)

Forecasting Strategies for Predicting Peak Electric Load Days

Science.gov (United States)

Saxena, Harshit

Academic institutions spend thousands of dollars every month on their electric power consumption. Some of these institutions follow a demand charges pricing structure; here the amount a customer pays to the utility is decided based on the total energy consumed during the month, with an additional charge based on the highest average power load required by the customer over a moving window of time as decided by the utility. Therefore, it is crucial for these institutions to minimize the time periods where a high amount of electric load is demanded over a short duration of time. In order to reduce the peak loads and have more uniform energy consumption, it is imperative to predict when these peaks occur, so that appropriate mitigation strategies can be developed. The research work presented in this thesis has been conducted for Rochester Institute of Technology (RIT), where the demand charges are decided based on a 15 minute sliding window panned over the entire month. This case study makes use of different statistical and machine learning algorithms to develop a forecasting strategy for predicting the peak electric load days of the month. The proposed strategy was tested for a whole year starting May 2015 to April 2016 during which a total of 57 peak days were observed. The model predicted a total of 74 peak days during this period, 40 of these cases were true positives, hence achieving an accuracy level of 70 percent. The results obtained with the proposed forecasting strategy are promising and demonstrate an annual savings potential worth about $80,000 for a single submeter of RIT.

Optical energy gaps and photoluminescence peaks of BaGa{sub 2}S{sub 4}:Er{sup 3+} and BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals

Energy Technology Data Exchange (ETDEWEB)

Choe, Sung-Hyu [Chosun University, Kwangju (Korea, Republic of); Jin, Moon-Seog [Dongshin University, Naju (Korea, Republic of); Kim, Wha-Tek [Chonnam National University, Kwangju (Korea, Republic of)

2005-12-15

BaGa{sub 2}S{sub 4}:Er{sup 3+} and BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the BaGa{sub 2}S{sub 4}:Er{sup 3+} and the BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals were found to be 4.045 eV and 3.073 eV, respectively, at 11 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Sharp emission peaks were observed in the photoluminescence spectra of the single crystals and assigned to radiation recombination between split Stark levels of the Er{sup 3+} ion.

Hydroclimatology of Dual Peak Cholera Incidence in Bengal Region: Inferences from a Spatial Explicit Model

Science.gov (United States)

Bertuzzo, E.; Mari, L.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2010-12-01

The seasonality of cholera and its relation with environmental drivers are receiving increasing interest and research efforts, yet they remain unsatisfactorily understood. A striking example is the observed annual cycle of cholera incidence in the Bengal region which exhibits two peaks despite the main environmental drivers that have been linked to the disease (air and sea surface temperature, zooplankton density, river discharge) follow a synchronous single-peak annual pattern. A first outbreak, mainly affecting the coastal regions, occurs in spring and it is followed, after a period of low incidence during summer, by a second, usually larger, peak in autumn also involving regions situated farther inland. A hydroclimatological explanation for this unique seasonal cycle has been recently proposed: the low river spring flows favor the intrusion of brackish water (the natural environment of the causative agent of the disease) which, in turn, triggers the first outbreak. The summer rising river discharges have a temporary dilution effect and prompt the repulsion of contaminated water which lowers the disease incidence. However, the monsoon flooding, together with the induced crowding of the population and the failure of the sanitation systems, can possibly facilitate the spatial transmission of the disease and promote the autumn outbreak. We test this hypothesis using a mechanistic, spatially explicit model of cholera epidemic. The framework directly accounts for the role of the river network in transporting and redistributing cholera bacteria among human communities as well as for the annual fluctuation of the river flow. The model is forced with the actual environmental drivers of the region, namely river flow and temperature. Our results show that these two drivers, both having a single peak in the summer, can generate a double peak cholera incidence pattern. Besides temporal patterns, the model is also able to qualitatively reproduce spatial patterns characterized

Peak regulation right

International Nuclear Information System (INIS)

Gao, Z. |; Ren, Z.; Li, Z.; Zhu, R.

2005-01-01

A peak regulation right concept and corresponding transaction mechanism for an electricity market was presented. The market was based on a power pool and independent system operator (ISO) model. Peak regulation right (PRR) was defined as a downward regulation capacity purchase option which allowed PRR owners to buy certain quantities of peak regulation capacity (PRC) at a specific price during a specified period from suppliers. The PRR owner also had the right to decide whether or not they would buy PRC from suppliers. It was the power pool's responsibility to provide competitive and fair peak regulation trading markets to participants. The introduction of PRR allowed for unit capacity regulation. The PRR and PRC were rated by the supplier, and transactions proceeded through a bidding process. PRR suppliers obtained profits by selling PRR and PRC, and obtained downward regulation fees regardless of whether purchases are made. It was concluded that the peak regulation mechanism reduced the total cost of the generating system and increased the social surplus. 6 refs., 1 tab., 3 figs

A study of the red-shift of a neutral donor bound exciton in GaN nanorods by hydrogenation.

Science.gov (United States)

Park, Byung-Guon; Lee, Sang-Tae; Reddeppa, Maddaka; Kim, Moon-Deock; Oh, Jae-Eung; Lee, Sang-Kwon

2017-09-08

In this paper we account for the physics behind the exciton peak shift in GaN nanorods (NRs) due to hydrogenation. GaN NRs were selectively grown on a patterned Ti/Si(111) substrate using plasma-assisted molecular beam epitaxy, and the effect of hydrogenation on their optical properties was investigated in detail using low-temperature photoluminescence measurements. Due to hydrogenation, the emissions corresponding to the donor-acceptor pair and yellow luminescence in GaN NRs were strongly suppressed, while the emission corresponding to the neutral to donor bound exciton (D 0 X) exhibited red-shift. Thermal annealing of hydrogenated GaN NRs demonstrated the recovery of the D 0 X and deep level emission. To determine the nature of the D 0 X peak shift due to hydrogenation, comparative studies were carried out on various diameters of GaN NRs, which can be controlled by different growth conditions and wet-etching times. Our experimental results reveal that the D 0 X shift depends on the diameter of the GaN NRs after hydrogenation. The results clearly demonstrate that the hydrogenation leads to band bending of GaN NRs as compensated by hydrogen ions, which causes a red-shift in the D 0 X emission.

A study of the red-shift of a neutral donor bound exciton in GaN nanorods by hydrogenation

Science.gov (United States)

Park, Byung-Guon; Lee, Sang-Tae; Reddeppa, Maddaka; Kim, Moon-Deock; Oh, Jae-Eung; Lee, Sang-Kwon

2017-09-01

In this paper we account for the physics behind the exciton peak shift in GaN nanorods (NRs) due to hydrogenation. GaN NRs were selectively grown on a patterned Ti/Si(111) substrate using plasma-assisted molecular beam epitaxy, and the effect of hydrogenation on their optical properties was investigated in detail using low-temperature photoluminescence measurements. Due to hydrogenation, the emissions corresponding to the donor-acceptor pair and yellow luminescence in GaN NRs were strongly suppressed, while the emission corresponding to the neutral to donor bound exciton (D0X) exhibited red-shift. Thermal annealing of hydrogenated GaN NRs demonstrated the recovery of the D0X and deep level emission. To determine the nature of the D0X peak shift due to hydrogenation, comparative studies were carried out on various diameters of GaN NRs, which can be controlled by different growth conditions and wet-etching times. Our experimental results reveal that the D0X shift depends on the diameter of the GaN NRs after hydrogenation. The results clearly demonstrate that the hydrogenation leads to band bending of GaN NRs as compensated by hydrogen ions, which causes a red-shift in the D0X emission.

Observation of single quantum dots in GaAs/AlAs micropillar cavities

Energy Technology Data Exchange (ETDEWEB)

Burger, Philipp; Karl, Matthias; Hu, Dongzhi; Schaadt, Daniel M.; Kalt, Heinz; Hetterich, Michael [Institut fuer Angewandte Physik, Universitaet Karlsruhe (Germany); DFG Center for Functional Nanostructures (CFN), Karlsruhe (Germany)

2009-07-01

In our contribution we present the fabrication steps of micropillar cavities and their optical properties. The layer structure consisting of a GaAs-based lambda-cavity sandwiched between two GaAs/AlAs distributed Bragg reflectors is grown by molecular-beam epitaxy. In(Ga)As quantum dots, emitting at around 950 nm, are embedded as optically active medium in the middle of the cavity. The pillars are milled out of this structure with a focused ion-beam. A confocal micro-photoluminescence set-up allows to measure optical cavity modes as well as single quantum dots in the pillars when using low excitation intensity. This enables us to observe a (thermal) shift of the single quantum dot peaks relative to the cavity mode. In addition, we increased the numerical aperture of the set-up (originally 0.4) with a solid immersion lens up to 0.8. Thus we are able to detect the fundamental mode of pillars with very small diameters. Furthermore, the collection efficiency increases substantially.

Anti-Zeno-effect recovery and Lamb-shift modification in modified vacuum

International Nuclear Information System (INIS)

Wang Dawei; Wang Ligang; Li Zhenghong; Zhu Shiyao

2009-01-01

The influence of the modification of the free vacuum on the quantum Zeno and anti-Zeno effects, as well as the Lamb (energy) shift of a multilevel atom, is studied. A unitary transformation method has been used to include the counter-rotating terms and to obtain the ground state of the whole Hamiltonian. The anti-Zeno effect is recovered if the modified density of states (DOS) has a dip near the transition frequency. The modification of DOS by a dip or a peak will change the Lamb shift compared with that in the free vacuum. Together with our unitary transformation method, there are three different methods to obtain the change in the Lamb shift. Using our method we investigate the change in the Lamb shift and obtain a formula for the change, which is the same as obtained with the method of Louisell [Quantum Statistical Properties of Radiation (Wiley, New York, 1973)] but different from the method of Cohen-Tannoudji et al. [Atom-Photon Interactions: Basic Processes and Applications (Wiley, New York, 1992), pp. 317 and 417]. The correctness of the Lamb shift formulas obtained by the three methods can be easily testified experimentally.

Saha equation, single and two particle states

International Nuclear Information System (INIS)

Kraeft, W.D.; Girardeau, M.D.; Strege, B.

1990-01-01

Single and two particle porperties in dense plasma are discussed in connection with their role in the mass action law for a partially ionized plasma. The two particle bound states are nearly density independent, while the continuum is essentially shifted. The single particle states are damped, and their energy has a negative shift and a parabolic behaviour for small momenta. (orig.)

Ketamine increases the frequency of electroencephalographic bicoherence peak on the alpha spindle area induced with propofol.

Science.gov (United States)

Hayashi, K; Tsuda, N; Sawa, T; Hagihira, S

2007-09-01

The reticular and thalamocortical system is known to play a prominent role in spindle wave activity, and the spindle wave is related to the sedative effects of anaesthetics. Recently, bispectral analysis of the EEG has been developed as a better method to indicate nonlinear regulation including the thalamocortical system linking to the cortical area. In the present study, in order to explore the interference of ketamine with the nonlinear regulation of the sub-cortical system, we examined the effect of ketamine on spindle alpha waves through the bispectral analysis. The study included 21 patients. Anaesthesia was induced and maintained using a propofol-TCI system (target-controlled infusion, with target concentration 3.5 microg ml(-1)). An A-2000 BIS monitor was used and the raw EEG signals were collected via an RS232 interface on a personal computer. Bicoherence, the normalized bispectrum, and power spectrum were analysed before and after i.v. administration of 1 mg kg(-1) racemic ketamine. Propofol caused alpha peaks in both power and bicoherence spectra, with average frequencies of 10.6 (SD 0.9) Hz and 10.7 (1.0) Hz, respectively. The addition of ketamine significantly shifted each peak to frequencies of 14.4 (1.4) Hz and 13.6 (1.5) Hz, respectively [P < 0.05, mean (SD)]. Ketamine shifted the alpha peaks of bicoherence induced by propofol to higher frequencies. This suggests that ketamine changes the alpha spindle rhythms through the modulation of the nonlinear sub-cortical reverberating network.

Impact of peak electricity demand in distribution grids: a stress test

NARCIS (Netherlands)

Hoogsteen, Gerwin; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria; Schuring, Friso; Kootstra, Ben

2015-01-01

The number of (hybrid) electric vehicles is growing, leading to a higher demand for electricity in distribution grids. To investigate the effects of the expected peak demand on distribution grids, a stress test with 15 electric vehicles in a single street is conducted and described in this paper.

The slightly-enriched spectral shift control reactor. Final report, September 30, 1988--September 30, 1991

Energy Technology Data Exchange (ETDEWEB)

Martin, W.R.; Lee, J.C.; Larsen, E.W. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering; Edlund, M.C. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical and Nuclear Engineering

1991-11-01

An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile {sup 238}U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC.

Multi-resonance peaks fiber Bragg gratings based on largely-chirped structure

Science.gov (United States)

Chen, Chao; Zhang, Xuan-Yu; Wei, Wei-Hua; Chen, Yong-Yi; Qin, Li; Ning, Yong-Qiang; Yu, Yong-Sen

2018-04-01

A composite fiber Bragg grating (FBG) with multi-resonance peaks (MRPs) has been realized by using femtosecond (fs) laser point-by-point inscription in single-mode fiber. This device contains a segment of largely-chirped gratings with the ultrahigh chirp coefficients and a segment of uniform high-order gratings. The observed MRPs are distributed in an ultra-broadband wavelength range from 1200 nm to 1700 nm in the form of quasi-period or multi-peak-group. For the 8th-order MRPs-FBG, we studied the axial strain and high-temperature sensing characteristics of different resonance peaks experimentally. Moreover, we have demonstrated a multi-wavelength fiber lasers with three-wavelength stable output by using a 9th-order MRPs-FBG as the wavelength selector. This work is significant for the fabrication and functionalization of FBGs with complicated spectra characteristics.

Anelastic relaxation peaks in single crystals of zirconium-oxygen alloys

International Nuclear Information System (INIS)

Ritchie, I.G.; Sprungmann, K.W.; Atrens, A.; Rosinger, H.E.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1977-01-01

Relaxations of the compliances S 11 -S 12 and S 44 have been observed in single crystals of zirconium-oxygen alloys tested in flexure and in torsion respectively. The relaxations are attributed to the stress-induced reorientation of substitutional impurity atoms (s) paired with interstitial oxygen atoms (i). The results demonstrate that the jump of the interstitial parallel to the basal plane dominates in the reorientation of the s-i pair

No effect of pinealectomy on the parallel shift in circadain rhythms of adrenocortical activity and food intake in blinded rats.

Science.gov (United States)

Takahashi, K; Inoue, K; Takahashi, Y

1976-10-01

Twenty-four-hr patterns of plasma corticosterone levels were determined at 4-hr intervals every 3-4 weeks in sighted and blinded pinealectomized rats of adult age. Through the whole period of the experiment, 24-hr patterns of food intake were also measured weekly. The sighted rats manifested the same 24-hr patterns of plasma corticosterone levels and food intake for 15 weeks after pinealectomy as those observed in the intact control rats. The magnitude of peak levels of plasma corticosterone and the amount of food intake did not differ between the two groups. A phase shift in circadian rhythms of plasma corticosterone levels and food intake was observed in both groups of blinded rats, with and without pinealectomy. Between the two groups, the patterns of phase shift were essentially similar for 10 weeks examined after optic enucleation. The peak elevation of plasma levels took place at 11 p.m. at the end of the 4th week after optic enucleation. Thereafter, 4- to 8-hr delay of peak appearance was observed every 3 weeks. No significant differences were found in peak values between the two groups of blinded rats. Furthermore, the circadian rhythm of food intake shifted in parallel with that of plasma corticosterone levels. A phase reversal of these two activities was observed between the 8th and 10th week after the operation. These results indicate that the pineal gland does not play any important role either in the maintenance of normal circadian periodicities of adrenocortical activity and food intake or in the shift in circadian rhythms of the two activities in the blinded rats.

Limitation of peak fitting and peak shape methods for determination of activation energy of thermoluminescence glow peaks

CERN Document Server

Sunta, C M; Piters, T M; Watanabe, S

1999-01-01

This paper shows the limitation of general order peak fitting and peak shape methods for determining the activation energy of the thermoluminescence glow peaks in the cases in which retrapping probability is much higher than the recombination probability and the traps are filled up to near saturation level. Right values can be obtained when the trap occupancy is reduced by using small doses or by post-irradiation partial bleaching. This limitation in the application of these methods has not been indicated earlier. In view of the unknown nature of kinetics in the experimental samples, it is recommended that these methods of activation energy determination should be applied only at doses well below the saturation dose.

Splitting of the excitonic peak in quantum wells with interfacial roughness

International Nuclear Information System (INIS)

Castella, H.; Wilkins, J.W.

1998-01-01

Excitons in a quantum well depend on the interfacial roughness resulting from its growth. The interface is characterized by islands of size ξ separated by one monolayer steps across which the confining potential decreases by V 0 for wider wells. A natural length is the localization length ξ 0 =πℎ/√ (2MV 0 ) characterizing the minimum size island to confine an exciton. For small islands (ξ 0 ), the absorption spectrum has a single exciton peak. As the island size ξ exceeds the localization length ξ 0 , the peak gradually splits into a doublet. Generally the spectra exhibit the following features: (1) the shape is very sensitive to ξ/ξ 0 and depends only weakly on the ratio of island size to exciton radius; (2) in the small island regime ξ 0 , the asymmetric shape of the exciton peak is correctly described by a model of white-noise potential, except for the position of the peak which still depends on the correlation length of the disorder. copyright 1998 The American Physical Society

Surface core-level shifts for simple metals

DEFF Research Database (Denmark)

Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

1994-01-01

screening, whereby a SCLS becomes equivalent to the surface segregation energy of a core-ionized atom, a quantity we obtain by separate bulk and surface impurity calculations. The results are in good agreement with experiment in most of those cases where the data originates from single-crystal measurements....... We discuss the surface shifts of the electrostatic potentials and the band centers in order to trace the microscopic origin of the SCLS in the simple metals and find that the anomalous subsurface core-level shifts in beryllium are caused by charge dipoles, which persist several layers into the bulk...

Aligning of single and multiple wavelength chromatographic

DEFF Research Database (Denmark)

Nielsen, Niels-Peter Vest; Carstensen, Jens Michael; Smedsgaard, Jørn

1998-01-01

optimised warping (COW) using two input parameters which can be estimated from the observed peak width. COW is demonstrated on constructed single trace chromatograms and on single and multiple wavelength chromatograms obtained from HPLC diode detection analyses of fungal extractsA copy of the C program......The use of chemometric data processing is becoming an important part of modern chromatography. Most chemometric analyses are performed on reduced data sets using areas of selected peaks detected in the chromatograms, which means a loss of data and introduces the problem of extracting peak data from...... to utilise the entire data matrix or rely on peak detection, thus having the same limitations as the commonly used chemometric procedures. The method presented uses the entire chromatographic data matrices and does not require any preprocessing e.g., peak detection. It relies on piecewise linear correlation...

The Spectral Shift Control Reactor as an option for much improved uranium utilisation in single-batch SMRs

Energy Technology Data Exchange (ETDEWEB)

Lindley, B.A., E-mail: bal29@cam.ac.uk; Parks, G.T.

2016-12-01

Highlights: • A PWR with mixed D{sub 2}O/H{sub 2}O moderator/coolant is investigated for SMR applications. • Heavy water concentration varied over the cycle to give ‘spectral shift’ operation. • Much wetter lattice than normal is neutronically favourable. • Taller fuel stack is thus needed to ensure acceptable MDNBR. • 35–43% increase in uranium utilisation for single batch reactor is possible. - Abstract: The Spectral Shift Control Reactor (SSCR) uses a mix of D{sub 2}O and H{sub 2}O to moderate and cool the reactor. Initially, a high proportion of D{sub 2}O is used, such that the reactor is substantially under-moderated, with excess neutrons being primarily captured in {sup 238}U, breeding {sup 239}Pu. Towards the end of the cycle (EOC), the coolant is predominantly H{sub 2}O, thermalising the neutron spectrum and increasing reactivity. Recently, small modular reactors (SMRs) have gained significant interest as a means of providing a power source that requires little maintenance and refuelling. This motivates long cycles and reduced batch operation. For a single-batch reactor, there is typically a 33% penalty to uranium utilisation compared to a 3-batch reactor. Lattice calculations demonstrate the potential of the SSCR to greatly improve uranium utilisation in single-batch reactors over a range of enrichments. A relatively ‘wet’ lattice is employed which further improves uranium utilisation. Cases with 5% and 15% fissile loading are considered, for which it is respectively possible to achieve 47% and 39% increases in natural uranium utilisation using the SSCR relative to a ‘reference’ light water reactor. In the latter case, if 25% thorium is mixed into the fuel, the improvement in uranium utilisation increases to a total of 49%. Hence, in both cases, it is possible to in effect eliminate the penalty of using a single fuel batch. The ‘wet’ lattice introduces substantial thermal-hydraulic challenges due to the significantly higher fuel

Make peak flow a habit

Science.gov (United States)

Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

Unravelling biology and shifting paradigms in cancer with single-cell sequencing.

Science.gov (United States)

Baslan, Timour; Hicks, James

2017-08-24

The fundamental operative unit of a cancer is the genetically and epigenetically innovative single cell. Whether proliferating or quiescent, in the primary tumour mass or disseminated elsewhere, single cells govern the parameters that dictate all facets of the biology of cancer. Thus, single-cell analyses provide the ultimate level of resolution in our quest for a fundamental understanding of this disease. Historically, this quest has been hampered by technological shortcomings. In this Opinion article, we argue that the rapidly evolving field of single-cell sequencing has unshackled the cancer research community of these shortcomings. From furthering an elemental understanding of intra-tumoural genetic heterogeneity and cancer genome evolution to illuminating the governing principles of disease relapse and metastasis, we posit that single-cell sequencing promises to unravel the biology of all facets of this disease.

Peak tree: a new tool for multiscale hierarchical representation and peak detection of mass spectrometry data.

Science.gov (United States)

Zhang, Peng; Li, Houqiang; Wang, Honghui; Wong, Stephen T C; Zhou, Xiaobo

2011-01-01

Peak detection is one of the most important steps in mass spectrometry (MS) analysis. However, the detection result is greatly affected by severe spectrum variations. Unfortunately, most current peak detection methods are neither flexible enough to revise false detection results nor robust enough to resist spectrum variations. To improve flexibility, we introduce peak tree to represent the peak information in MS spectra. Each tree node is a peak judgment on a range of scales, and each tree decomposition, as a set of nodes, is a candidate peak detection result. To improve robustness, we combine peak detection and common peak alignment into a closed-loop framework, which finds the optimal decomposition via both peak intensity and common peak information. The common peak information is derived and loopily refined from the density clustering of the latest peak detection result. Finally, we present an improved ant colony optimization biomarker selection method to build a whole MS analysis system. Experiment shows that our peak detection method can better resist spectrum variations and provide higher sensitivity and lower false detection rates than conventional methods. The benefits from our peak-tree-based system for MS disease analysis are also proved on real SELDI data.

Larger red-shift in optical emissions obtained from the thin films of globular proteins (BSA, lysozyme) – polyelectrolyte (PAA) complexes

Energy Technology Data Exchange (ETDEWEB)

Talukdar, Hrishikesh [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati 781035, Assam (India); Kundu, Sarathi, E-mail: sarathi.kundu@gmail.com [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati 781035, Assam (India); Basu, Saibal [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2016-09-30

Graphical abstract: Thin films of protein-polyelectrolyte complexes show larger red-shift in optical emission. - Highlights: • Globular proteins (lysozyme and BSA) and polyelectrolyte (sodium polyacrylic acid) are used to form protein-polyelectrolyte complexes (PPC). • Larger red-shift in optical emission is obtained from the thin films of PPC. • Red-shift is not obtained from the solution of PPC and pure protein thin films. • Larger red-shift from PPC films is due to the energy dissipation as non-radiative form through interactions with nearby atoms. • Red-shift in optical emission is independent on the thickness of the PPC film. - Abstract: Globular proteins (lysozyme and BSA) and polyelectrolyte (sodium polyacrylic acid) are used to form protein-polyelectrolyte complexes (PPC). Out-of-plane structures of ≈30–60 nm thick PPC films and their surface morphologies have been studied by using X-ray reflectivity and atomic force microscopy, whereas optical behaviors of PPC and protein conformations have been studied by using UV–vis, photoluminescence and FTIR spectroscopy respectively. Our study reveals that thin films of PPC show a larger red-shift of 23 and 16 nm in the optical emissions in comparison to that of pure protein whereas bulk PPC show a small blue-shift of ≈3 nm. A small amount of peak-shift is found to occur due to the heat treatment or concentration variation of the polyelectrolyte/protein in bulk solution but cannot produce such film thickness independent larger red-shift. Position of the emission peak remains nearly unchanged with the film thickness. Mechanism for such larger red-shift has been proposed.

Frequency shift of the Bragg and Non-Bragg backscattering from periodic water wave

Science.gov (United States)

Wen, Biyang; Li, Ke

2016-08-01

Doppler effect is used to measure the relative speed of a moving target with respect to the radar, and is also used to interpret the frequency shift of the backscattering from the ocean wave according to the water-wave phase velocity. The widely known relationship between the Doppler shift and the water-wave phase velocity was deduced from the scattering measurements data collected from actual sea surface, and has not been verified under man-made conditions. Here we show that this ob- served frequency shift of the scattering data from the Bragg and Non-Bragg water wave is not the Doppler shift corresponding to the water-wave phase velocity as commonly believed, but is the water-wave frequency and its integral multiple frequency. The power spectrum of the backscatter from the periodic water wave consists of serials discrete peaks, which is equally spaced by water wave frequency. Only when the water-wave length is the integer multiples of the Bragg wave, and the radar range resolution is infinite, does the frequency shift of the backscattering mathematically equal the Doppler shift according to the water-wave phase velocity.

Red shift of near band edge emission in cerium implanted GaN

International Nuclear Information System (INIS)

Majid, Abdul; Ali, Akbar

2009-01-01

Rare earth (RE) doping in GaN is a promising technology to control the optical properties. However, there are no reports on doping of cerium (Ce) into GaN, which is a very unique RE element. In this paper, we performed photoluminescence (PL) and optical transmission measurements on Ce-doped GaN for the first time. A significant red shift of about 120 meV was observed in the PL peak position of the donor bound excitons. This red shift of near band emission was corroborated by the red shift of the absorption edge related to GaN in the optical transmission measurements. This observation is attributed to the band gap narrowing in GaN heavily doped with Ce. The activation energy of the Ce-related shallow donor is found to be 21.9 meV in GaN.

Red shift of near band edge emission in cerium implanted GaN

Energy Technology Data Exchange (ETDEWEB)

Majid, Abdul; Ali, Akbar, E-mail: abdulmajid40@yahoo.co, E-mail: akbar@qau.edu.p [Advance Materials Physics Laboratory, Physics Department, Quaid-i-Azam University, Islamabad (Pakistan)

2009-02-21

Rare earth (RE) doping in GaN is a promising technology to control the optical properties. However, there are no reports on doping of cerium (Ce) into GaN, which is a very unique RE element. In this paper, we performed photoluminescence (PL) and optical transmission measurements on Ce-doped GaN for the first time. A significant red shift of about 120 meV was observed in the PL peak position of the donor bound excitons. This red shift of near band emission was corroborated by the red shift of the absorption edge related to GaN in the optical transmission measurements. This observation is attributed to the band gap narrowing in GaN heavily doped with Ce. The activation energy of the Ce-related shallow donor is found to be 21.9 meV in GaN.

Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

Energy Technology Data Exchange (ETDEWEB)

Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila; Xu, Peng

2006-04-06

California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. (3) Determine how customers

Two-peaked 5-ALA-induced PpIX fluorescence emission spectrum distinguishes glioblastomas from low grade gliomas and infiltrative component of glioblastomas.

Science.gov (United States)

Montcel, Bruno; Mahieu-Williame, Laurent; Armoiry, Xavier; Meyronet, David; Guyotat, Jacques

2013-04-01

5-ALA-induced protoporphyrin IX (PpIX) fluorescence enables to guiding in intra-operative surgical glioma resection. However at present, it has yet to be shown that this method is able to identify infiltrative component of glioma. In extracted tumor tissues we measured a two-peaked emission in low grade gliomas and in the infiltrative component of glioblastomas due to multiple photochemical states of PpIX. The second emission peak appearing at 620 nm (shifted by 14 nm from the main peak at 634 nm) limits the sensibility of current methods to measured PpIX concentration. We propose new measured parameters, by taking into consideration the two-peaked emission, to overcome these limitations in sensitivity. These parameters clearly distinguish the solid component of glioblastomas from low grade gliomas and infiltrative component of glioblastomas.

Peak Experience Project

Science.gov (United States)

Scott, Daniel G.; Evans, Jessica

2010-01-01

This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

PONDEROSA, an automated 3D-NOESY peak picking program, enables automated protein structure determination.

Science.gov (United States)

Lee, Woonghee; Kim, Jin Hae; Westler, William M; Markley, John L

2011-06-15

PONDEROSA (Peak-picking Of Noe Data Enabled by Restriction of Shift Assignments) accepts input information consisting of a protein sequence, backbone and sidechain NMR resonance assignments, and 3D-NOESY ((13)C-edited and/or (15)N-edited) spectra, and returns assignments of NOESY crosspeaks, distance and angle constraints, and a reliable NMR structure represented by a family of conformers. PONDEROSA incorporates and integrates external software packages (TALOS+, STRIDE and CYANA) to carry out different steps in the structure determination. PONDEROSA implements internal functions that identify and validate NOESY peak assignments and assess the quality of the calculated three-dimensional structure of the protein. The robustness of the analysis results from PONDEROSA's hierarchical processing steps that involve iterative interaction among the internal and external modules. PONDEROSA supports a variety of input formats: SPARKY assignment table (.shifts) and spectrum file formats (.ucsf), XEASY proton file format (.prot), and NMR-STAR format (.star). To demonstrate the utility of PONDEROSA, we used the package to determine 3D structures of two proteins: human ubiquitin and Escherichia coli iron-sulfur scaffold protein variant IscU(D39A). The automatically generated structural constraints and ensembles of conformers were as good as or better than those determined previously by much less automated means. The program, in the form of binary code along with tutorials and reference manuals, is available at http://ponderosa.nmrfam.wisc.edu/.

Influence of shift work on the physical work capacity of Tunisian nurses: a cross-sectional study in two university hospitals.

Science.gov (United States)

Merchaoui, Irtyah; Bouzgarrou, Lamia; Mnasri, Ahlem; Mghanem, Mounir; Akrout, Mohamed; Malchaire, Jacques; Chaari, Neila

2017-01-01

This study has been performed to determine the influence of rotating shift work on physical working capacity of Tunisian nurses and to design recommendations to managers so that they implement effective preventive measures. It is a cross-sectional design using a standardized questionnaire and many physical capacity tests on a representative sample of 1181 nurses and nursing assistants from two university hospital centers of the school of Medicine of Monastir located in the Tunisian Sahel. 293 participants have been recruited by stratified random sampling according to gender and departments. Maximum Grip strength, 30s sit-to-stand test, one leg test, Fingertip-to-Floor test, Saltsa test and peak expiratory flow were used to assess physical capacity. Work ability was assessed through the workability index. Mental and physical loads were heavily perceived in shift healthcare workers (p=0.01; p=0.02). The maximum grip force was stronger in rotating shift work nurses (p=0.0001). Regarding to the seniority subgroups in each kind of work schedule, the Body Mass Index was increasing with seniority in both schedules. All the physical tests, were better in less-than-ten-year groups. Peak Flow and grip strength were significantly better in less-than-ten-year seniority in shift work group. There is a need to improve the design of the existing shift systems and to reduce as much as possible shift schedule as well as to avoid shift schedule for over-10-year-seniority nurses.

Probabilistic peak detection in CE-LIF for STR DNA typing.

Science.gov (United States)

Woldegebriel, Michael; van Asten, Arian; Kloosterman, Ate; Vivó-Truyols, Gabriel

2017-07-01

In this work, we present a novel probabilistic peak detection algorithm based on a Bayesian framework for forensic DNA analysis. The proposed method aims at an exhaustive use of raw electropherogram data from a laser-induced fluorescence multi-CE system. As the raw data are informative up to a single data point, the conventional threshold-based approaches discard relevant forensic information early in the data analysis pipeline. Our proposed method assigns a posterior probability reflecting the data point's relevance with respect to peak detection criteria. Peaks of low intensity generated from a truly existing allele can thus constitute evidential value instead of fully discarding them and contemplating a potential allele drop-out. This way of working utilizes the information available within each individual data point and thus avoids making early (binary) decisions on the data analysis that can lead to error propagation. The proposed method was tested and compared to the application of a set threshold as is current practice in forensic STR DNA profiling. The new method was found to yield a significant improvement in the number of alleles identified, regardless of the peak heights and deviation from Gaussian shape. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shift Colors

Science.gov (United States)

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PPM-One: a static protein structure based chemical shift predictor

International Nuclear Information System (INIS)

Li, Dawei; Brüschweiler, Rafael

2015-01-01

We mined the most recent editions of the BioMagResDataBank and the protein data bank to parametrize a new empirical knowledge-based chemical shift predictor of protein backbone atoms using either a linear or an artificial neural network model. The resulting chemical shift predictor PPM-One accepts a single static 3D structure as input and emulates the effect of local protein dynamics via interatomic steric contacts. Furthermore, the chemical shift prediction was extended to most side-chain protons and it is found that the prediction accuracy is at a level allowing an independent assessment of stereospecific assignments. For a previously established set of test proteins some overall improvement was achieved over current top-performing chemical shift prediction programs

Residential demand response reduces air pollutant emissions on peak electricity demand days in New York City

International Nuclear Information System (INIS)

Gilbraith, Nathaniel; Powers, Susan E.

2013-01-01

Many urban areas in the United States have experienced difficulty meeting the National Ambient Air Quality Standards (NAAQS), partially due to pollution from electricity generating units. We evaluated the potential for residential demand response to reduce pollutant emissions on days with above average pollutant emissions and a high potential for poor air quality. The study focused on New York City (NYC) due to non-attainment with NAAQS standards, large exposed populations, and the existing goal of reducing pollutant emissions. The baseline demand response scenario simulated a 1.8% average reduction in NYC peak demand on 49 days throughout the summer. Nitrogen oxide and particulate matter less than 2.5 μm in diameter emission reductions were predicted to occur (−70, −1.1 metric tons (MT) annually), although, these were not likely to be sufficient for NYC to meet the NAAQS. Air pollution mediated damages were predicted to decrease by $100,000–$300,000 annually. A sensitivity analysis predicted that substantially larger pollutant emission reductions would occur if electricity demand was shifted from daytime hours to nighttime hours, or the total consumption decreased. Policies which incentivize shifting electricity consumption away from periods of high human and environmental impacts should be implemented, including policies directed toward residential consumers. - Highlights: • The impact of residential demand response on air emissions was modeled. • Residential demand response will decrease pollutant emissions in NYC. • Emissions reductions occur during periods with high potential for poor air quality. • Shifting demand to nighttime hours was more beneficial than to off-peak daytime hours

Photoluminescence and structural properties of unintentional single and double InGaSb/GaSb quantum wells grown by MOVPE

Science.gov (United States)

Ahia, Chinedu Christian; Tile, Ngcali; Botha, Johannes R.; Olivier, E. J.

2018-04-01

The structural and photoluminescence (PL) characterization of InGaSb quantum well (QW) structures grown on GaSb substrate (100) using atmospheric pressure Metalorganic Vapor Phase Epitaxy (MOVPE) is presented. Both structures (single and double-InGaSb QWs) were inadvertently formed during an attempt to grow capped InSb/GaSb quantum dots (QDs). In this work, 10 K PL peak energies at 735 meV and 740 meV are suggested to be emissions from the single and double QWs, respectively. These lines exhibit red shifts, accompanied by a reduction in their full-widths at half-maximum (FWHM) as the excitation power decreases. The presence of a GaSb spacer in the double QW was found to increase the strength of the PL emission, which consequently gives rise to a reduced blue-shift and broadening of the PL emission line observed for the double QW with an increase in laser power, while the low thermal activation energy for the quenching of the PL from the double QW is attributed to the existence of threading dislocations, as seen in the bright field TEM image for this sample.

The Nature of Double-peaked [O III] Active Galactic Nuclei

Science.gov (United States)

Fu, Hai; Yan, Lin; Myers, Adam D.; Stockton, Alan; Djorgovski, S. G.; Aldering, G.; Rich, Jeffrey A.

2012-01-01

Active galactic nuclei (AGNs) with double-peaked [O III] lines are suspected to be sub-kpc or kpc-scale binary AGNs. However, pure gas kinematics can produce the same double-peaked line profile in spatially integrated spectra. Here we combine integral-field spectroscopy and high-resolution imaging of 42 double-peaked [O III] AGNs from the Sloan Digital Sky Survey to investigate the constituents of the population. We find two binary AGNs where the line splitting is driven by the orbital motion of the merging nuclei. Such objects account for only ~2% of the double-peaked AGNs. Almost all (~98%) of the double-peaked AGNs were selected because of gas kinematics; and half of those show spatially resolved narrow-line regions that extend 4-20 kpc from the nuclei. Serendipitously, we find two spectrally unresolved binary AGNs where gas kinematics produced the double-peaked [O III] lines. The relatively frequent serendipitous discoveries indicate that only ~1% of binary AGNs would appear double-peaked in Sloan spectra and 2.2+2.5 -0.8% of all Sloan AGNs are binary AGNs. Therefore, the double-peaked sample does not offer much advantage over any other AGN samples in finding binary AGNs. The binary AGN fraction implies an elevated AGN duty cycle (8+8 -3%), suggesting galaxy interactions enhance nuclear accretion. We illustrate that integral-field spectroscopy is crucial for identifying binary AGNs: several objects previously classified as "binary AGNs" with long-slit spectra are most likely single AGNs with extended narrow-line regions (ENLRs). The formation of ENLRs driven by radiation pressure is also discussed. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Phase-shifted Bragg grating inscription in PMMA microstructured POF using 248 nm UV radiation

OpenAIRE

Pereira, L.; Pospori, A.; Antunes, Paulo; Domingues, Maria Fatima; Marques, S.; Bang, Ole; Webb, David J.; Marques, Carlos A.F.

2017-01-01

In this work we experimentally validate and characterize the first phase-shifted polymer optical fiber Bragg gratings (PS-POFBGs) produced using a single pulse from a 248 nm krypton fluoride laser. A single-mode poly (methyl methacrylate) optical fiber with a core doped with benzyl dimethyl ketal for photosensitivity improvement was used. A uniform phase mask customized for 850 nm grating inscription was used to inscribe these Bragg structures. The phase shift defect was created directly duri...

Getting Your Peaks in Line: A Review of Alignment Methods for NMR Spectral Data

Directory of Open Access Journals (Sweden)

Trung Nghia Vu

2013-04-01

Full Text Available One of the most significant challenges in the comparative analysis of Nuclear Magnetic Resonance (NMR metabolome profiles is the occurrence of shifts between peaks across different spectra, for example caused by fluctuations in pH, temperature, instrument factors and ion content. Proper alignment of spectral peaks is therefore often a crucial preprocessing step prior to downstream quantitative analysis. Various alignment methods have been developed specifically for this purpose. Other methods were originally developed to align other data types (GC, LC, SELDI-MS, etc., but can also be applied to NMR data. This review discusses the available methods, as well as related problems such as reference determination or the evaluation of alignment quality. We present a generic alignment framework that allows for comparison and classification of different alignment approaches according to their algorithmic principles, and we discuss their performance.

Stark shift measurements of Xe II and Xe III spectral lines

International Nuclear Information System (INIS)

Cirisan, M; Pelaez, R J; Djurovic, S; Aparicio, J A; Mar, S

2007-01-01

Stark shift measurements of singly and doubly ionized Xe spectral lines are presented in this paper. Shifts of 110 Xe II lines and 42 Xe III lines are reported, including a significant number of new results. A low-pressure-pulsed arc with 95% of He and 5% of Xe was used as a plasma source. All measurements were performed under the following plasma conditions: electron density (0.2-1.4) x 10 23 m -3 and electron temperature 18 000-23 000 K. The measured Stark shifts are compared with other experimental and theoretical data

Plasmid DNA damage by heavy ions at spread-out Bragg peak energies

NARCIS (Netherlands)

Dang, H. M.; van Goethem, M. J.; van der Graaf, E. R.; Brandenburg, S.; Hoekstra, R.; Schlatholter, T.

2010-01-01

Interaction of ionizing radiation with plasmid DNA can lead to formation of single strand breaks, double strand breaks and clustered lesions. We have investigated the response of the synthetic plasmid pBR322 in aqueous solution upon irradiation with (12)C ions under spread-out Bragg peak conditions

Grating-based x-ray differential phase contrast imaging with twin peaks in phase-stepping curves—phase retrieval and dewrapping

Energy Technology Data Exchange (ETDEWEB)

Yang, Yi; Xie, Huiqiao; Tang, Xiangyang, E-mail: xiangyang.tang@emory.edu [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States); Cai, Weixing [Department of Radiation Oncology, Brigham and Women’s Hospital Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115 (United States); Mao, Hui [Laboratory of Functional and Molecular Imaging and Nanomedicine, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, Georgia 30329 (United States)

2016-06-15

Purpose: X-ray differential phase contrast CT implemented with Talbot interferometry employs phase-stepping to extract information of x-ray attenuation, phase shift, and small-angle scattering. Since inaccuracy may exist in the absorption grating G{sub 2} due to an imperfect fabrication, the effective period of G{sub 2} can be as large as twice the nominal period, leading to a phenomenon of twin peaks that differ remarkably in their heights. In this work, the authors investigate how to retrieve and dewrap the phase signal from the phase-stepping curve (PSC) with the feature of twin peaks for x-ray phase contrast imaging. Methods: Based on the paraxial Fresnel–Kirchhoff theory, the analytical formulae to characterize the phenomenon of twin peaks in the PSC are derived. Then an approach to dewrap the retrieved phase signal by jointly using the phases of the first- and second-order Fourier components is proposed. Through an experimental investigation using a prototype x-ray phase contrast imaging system implemented with Talbot interferometry, the authors evaluate and verify the derived analytic formulae and the proposed approach for phase retrieval and dewrapping. Results: According to theoretical analysis, the twin-peak phenomenon in PSC is a consequence of combined effects, including the inaccuracy in absorption grating G{sub 2}, mismatch between phase grating and x-ray source spectrum, and finite size of x-ray tube’s focal spot. The proposed approach is experimentally evaluated by scanning a phantom consisting of organic materials and a lab mouse. The preliminary data show that compared to scanning G{sub 2} over only one single nominal period and correcting the measured phase signal with an intuitive phase dewrapping method that is being used in the field, stepping G{sub 2} over twice its nominal period and dewrapping the measured phase signal with the proposed approach can significantly improve the quality of x-ray differential phase contrast imaging in both

Predictors of the peak width for networks with exponential links

Science.gov (United States)

Troutman, B.M.; Karlinger, M.R.

1989-01-01

We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations of S and T given network magnitude N and given mainstream length H. In addition, a simulation study is performed to examine various predictors of S and T, including N, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor of S is N, of T is H, and of the scaled peak (S divided by the area under the width function) is H. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predicting S and T despite probable violations of the original assumptions. ?? 1989 Springer-Verlag.

Lanthanide shift reagents, binding, shift mechanisms and exchange

International Nuclear Information System (INIS)

Boer, J.W.M. de

1977-01-01

Paramagnetic lanthanide shift reagents, when added to a solution of a substrate, induce shifts in the nuclear magnetic resonance (NMR) spectrum of the substrate molecules. The induced shifts contain information about the structure of the shift reagent substrate complex. The structural information, however, may be difficult to extract because of the following effects: (1) different complexes between shift reagent and substrate may be present in solution, e.g. 1:1 and 1:2 complexes, and the shift observed is a weighed average of the shifts of the substrate nuclei in the different complexes; (2) the Fermi contact interaction, arising from the spin density at the nucleus, contributes to the induced shift; (3) chemical exchange effects may complicate the NMR spectrum. In this thesis, the results of an investigation into the influence of these effects on the NMR spectra of solutions containing a substrate and LSR are presented. The equations describing the pseudo contact and the Fermi contact shift are derived. In addition, it is shown how the modified Bloch equations describing the effect of the chemical exchange processes occurring in the systems studied can be reduced to the familiar equations for a two-site exchange case. The binding of mono- and bifunctional ethers to the shift reagent are reported. An analysis of the induced shifts is given. Finally, the results of the experiments performed to study the exchange behavior of dimethoxyethane and heptafluorodimethyloctanedionato ligands are presented

Projection Effects of Large-scale Structures on Weak-lensing Peak Abundances

Science.gov (United States)

Yuan, Shuo; Liu, Xiangkun; Pan, Chuzhong; Wang, Qiao; Fan, Zuhui

2018-04-01

High peaks in weak lensing (WL) maps originate dominantly from the lensing effects of single massive halos. Their abundance is therefore closely related to the halo mass function and thus a powerful cosmological probe. However, besides individual massive halos, large-scale structures (LSS) along lines of sight also contribute to the peak signals. In this paper, with ray-tracing simulations, we investigate the LSS projection effects. We show that for current surveys with a large shape noise, the stochastic LSS effects are subdominant. For future WL surveys with source galaxies having a median redshift z med ∼ 1 or higher, however, they are significant. For the cosmological constraints derived from observed WL high-peak counts, severe biases can occur if the LSS effects are not taken into account properly. We extend the model of Fan et al. by incorporating the LSS projection effects into the theoretical considerations. By comparing with simulation results, we demonstrate the good performance of the improved model and its applicability in cosmological studies.

Peak Oil and other threatening peaks-Chimeras without substance

International Nuclear Information System (INIS)

Radetzki, Marian

2010-01-01

The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

The effect of utility time-varying pricing and load control strategies on residential summer peak electricity use. A review

International Nuclear Information System (INIS)

Newsham, Guy R.; Bowker, Brent G.

2010-01-01

Peak demand for electricity in North America is expected to grow, challenging electrical utilities to supply this demand in a cost-effective, reliable manner. Therefore, there is growing interest in strategies to reduce peak demand by eliminating electricity use, or shifting it to non-peak times. This strategy is commonly called 'demand response'. In households, common strategies are time-varying pricing, which charge more for energy use on peak, or direct load control, which allows utilities to curtail certain loads during high demand periods. We reviewed recent North American studies of these strategies. The data suggest that the most effective strategy is a critical peak price (CPP) program with enabling technology to automatically curtail loads on event days. There is little evidence that this causes substantial hardship for occupants, particularly if they have input into which loads are controlled and how, and have an override option. In such cases, a peak load reduction of at least 30% is a reasonable expectation. It might be possible to attain such load reductions without enabling technology by focusing on household types more likely to respond, and providing them with excellent support. A simple time-of-use (TOU) program can only expect to realise on-peak reductions of 5%. (author)

Evidence for two distinct defects contributing to the H4 deep-level transient spectroscopy peak in electron-irradiated InP

International Nuclear Information System (INIS)

Darwich, R.; Massarani, B.; Kaaka, M.; Awad, F.

2000-01-01

Deep-level transient spectroscopy (DLTS) has been used to study the dominant deep-level H4 produced in InP by electron irradiation. The characteristics of the H4 peak in Zn-doped Inp has been studied as a function of pulse duration (t p ) before and after annealing. The results show that at least two traps contribute to the H4 peak: one is a fast trap (labeled H4 f ) and the other is a show trap (labeled H4 s ). This is show through several results concerning the activation energy, the capture cross section, the full width at half-maximum, and the peak temperature shift. It is shown that both traps are irradiation defects created in P sublattice. (authors)

Tilt shift determinations with spatial-carrier phase-shift method in temporal phase-shift interferometry

International Nuclear Information System (INIS)

Liu, Qian; Wang, Yang; He, Jianguo; Ji, Fang; Wang, Baorui

2014-01-01

An algorithm is proposed to deal with tilt-shift errors in temporal phase-shift interferometry (PSI). In the algorithm, the tilt shifts are detected with the spatial-carrier phase-shift (SCPS) method and then the tilt shifts are applied as priori information to the least-squares fittings of phase retrieval. The algorithm combines the best features of the SCPS and the temporal PSI. The algorithm could be applied to interferograms of arbitrary aperture without data extrapolation for the Fourier transform is not involved. Simulations and experiments demonstrate the effectiveness of the algorithm. The statistics of simulation results show a satisfied accuracy in detecting tilt-shift errors. Comparisons of the measurements with and without environmental vibration show that the proposed algorithm could compensate tilt-shift errors and retrieve wavefront phase accurately. The algorithm provides an approach to retrieve wavefront phase for the temporal PSI in vibrating environment. (paper)

Single crystal and optical ceramic multicomponent garnet scintillators: A comparative study

International Nuclear Information System (INIS)

Wu, Yuntao; Luo, Zhaohua; Jiang, Haochuan; Meng, Fang; Koschan, Merry; Melcher, Charles L.

2015-01-01

Multicomponent garnet materials can be made in optical ceramic as well as single crystal form due to their cubic crystal structure. In this work, high-quality Gd 3 Ga 3 Al 2 O 12 :0.2 at% Ce (GGAG:Ce) single crystal and (Gd,Lu) 3 Ga 3 Al 2 O 12 :1 at% Ce (GLuGAG:Ce) optical ceramics were fabricated by the Czochralski method and a combination of hot isostatic pressing (HIPing) and annealing treatment, respectively. Under optical and X-ray excitation, the GLuGAG:Ce optical ceramic exhibits a broad Ce 3+ transition emission centered at 550 nm, while the emission peak of the GGAG:Ce single crystal is centered at 540 nm. A self-absorption effect in GLuGAG:Ce optical ceramic results in this red-shift of the Ce 3+ emission peak compared to that in the GGAG:Ce single crystal. The light yield under 662 keV γ-ray excitation was 45,000±2500 photons/MeV and 48,200±2410 photons/MeV for the GGAG:Ce single crystal and GLuGAG:Ce optical ceramic, respectively. An energy resolution of 7.1% for 662 keV γ-rays was achieved in the GLuGAG:Ce optical ceramic with a Hamamatsu R6231 PMT, which is superior to the value of 7.6% for a GGAG:Ce single crystal. Scintillation decay time measurements under 137 Cs irradiation show two exponential decay components of 58 ns (47%) and 504 ns (53%) for the GGAG:Ce single crystal, and 84 ns (76%) and 148 ns (24%) for the GLuGAG:Ce optical ceramic. The afterglow level after X-ray cutoff in the GLuGAG:Ce optical ceramic is at least one order of magnitude lower than in the GGAG:Ce single crystal. - Highlights: • GGAG:Ce single crystal and GLuGAG:Ce optical ceramics were fabricated. • The light yield of both ceramic and crystal G(Lu)GAG:Ce reached the level of 45,000 photons/MeV. • GLuGAG:Ce optical ceramic showed a better energy resolution of 7.1% for 662 keV. • GLuGAG:Ce ceramics exhibited lower afterglow level than that of GGAG:Ce single crystals. • The possible optimization strategies for multicomponent aluminate garnets are discussed

Double peak-induced distance error in short-time-Fourier-transform-Brillouin optical time domain reflectometers event detection and the recovery method.

Science.gov (United States)

Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi

2015-10-01

The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system.

Dye shift: a neglected source of genotyping error in molecular ecology.

Science.gov (United States)

Sutton, Jolene T; Robertson, Bruce C; Jamieson, Ian G

2011-05-01

Molecular ecologists must be vigilant in detecting and accounting for genotyping error, yet potential errors stemming from dye-induced mobility shift (dye shift) may be frequently neglected and largely unknown to researchers who employ 3-primer systems with automated genotyping. When left uncorrected, dye shift can lead to mis-scoring alleles and even to falsely calling new alleles if different dyes are used to genotype the same locus in subsequent reactions. When we used four different fluorophore labels from a standard dye set to genotype the same set of loci, differences in the resulting size estimates for a single allele ranged from 2.07 bp to 3.68 bp. The strongest effects were associated with the fluorophore PET, and relative degree of dye shift was inversely related to locus size. We found little evidence in the literature that dye shift is regularly accounted for in 3-primer studies, despite knowledge of this phenomenon existing for over a decade. However, we did find some references to erroneous standard correction factors for the same set of dyes that we tested. We thus reiterate the need for strict quality control when attempting to reduce possible sources of genotyping error, and in cases where different dyes are applied to a single locus, perhaps mistakenly, we strongly discourage researchers from assuming generic correction patterns. © 2011 Blackwell Publishing Ltd.

The effects of acute alcohol on psychomotor, set-shifting, and working memory performance in older men and women.

Science.gov (United States)

Hoffman, Lauren A; Sklar, Alfredo L; Nixon, Sara Jo

2015-05-01

A limited number of publications have documented the effects of acute alcohol administration among older adults. Among these, only a few have investigated sex differences within this population. The current project examined the behavioral effects of acute low- and moderate-dose alcohol on 62 older (ages 55-70) male and female, healthy, light to moderate drinkers. Participants were randomly assigned to one of three dose conditions: placebo (peak breath alcohol concentration [BrAC] of 0 mg/dL), low (peak BrAC of 40 mg/dL), and moderate (peak BrAC of 65 mg/dL). Tasks assessed psychomotor, set-shifting, and working memory performance. Better set-shifting abilities were observed among women, whereas men demonstrated more efficient working memory, regardless of dose. The moderate-dose group did not significantly differ from the placebo group on any task. However, the low-dose group performed better than the moderate-dose group across measures of set shifting and working memory. Relative to the placebo group, the low-dose group exhibited better working memory, specifically for faces. Interestingly, there were no sex by dose interactions. These data suggest that, at least for our study's task demands, low and moderate doses of alcohol do not significantly hinder psychomotor, set-shifting, or working memory performance among older adults. In fact, low-dose alcohol may facilitate certain cognitive abilities. Furthermore, although sex differences in cognitive abilities were observed, these alcohol doses did not differentially affect men and women. Further investigation is necessary to better characterize the effects of sex and alcohol dose on cognition in older adults. Copyright © 2015 Elsevier Inc. All rights reserved.

Dynamical resonance shift and unification of resonances in short-pulse laser-cluster interaction

Science.gov (United States)

Mahalik, S. S.; Kundu, M.

2018-06-01

Pronounced maximum absorption of laser light irradiating a rare-gas or metal cluster is widely expected during the linear resonance (LR) when Mie-plasma wavelength λM of electrons equals the laser wavelength λ . On the contrary, by performing molecular dynamics (MD) simulations of an argon cluster irradiated by short 5-fs (FWHM) laser pulses it is revealed that, for a given laser pulse energy and a cluster, at each peak intensity there exists a λ —shifted from the expected λM—that corresponds to a unified dynamical LR at which evolution of the cluster happens through very efficient unification of possible resonances in various stages, including (i) the LR in the initial time of plasma creation, (ii) the LR in the Coulomb expanding phase in the later time, and (iii) anharmonic resonance in the marginally overdense regime for a relatively longer pulse duration, leading to maximum laser absorption accompanied by maximum removal of electrons from cluster and also maximum allowed average charge states for the argon cluster. Increasing the laser intensity, the absorption maxima is found to shift to a higher wavelength in the band of λ ≈(1 -1.5 ) λM than permanently staying at the expected λM. A naive rigid sphere model also corroborates the wavelength shift of the absorption peak as found in MD and unequivocally proves that maximum laser absorption in a cluster happens at a shifted λ in the marginally overdense regime of λ ≈(1 -1.5 ) λM instead of λM of LR. The present study is important for guiding an optimal condition laser-cluster interaction experiment in the short-pulse regime.

Analysis of the same day of the week increases in peak electricity ...

African Journals Online (AJOL)

Modelling of the same day of the week increases in peak electricity demand improves the reliability of a power network if an accurate assessment of the level and frequency of future extreme load forecasts is carried out. Key words: Gibbs sampling, generalized single pareto, generalized pareto distribution, pareto quantile ...

Many-body calculation of the coincidence L3 photoelectron spectroscopy main line of Ni metal

International Nuclear Information System (INIS)

Ohno, Masahide

2008-01-01

The partial singles L 3 photoelectron spectroscopy (PES) main line of Ni metal correlated with Auger electrons emitted by the localized L 3 -VV Auger decay is calculated by a many-body theory. The partial singles L 3 PES main line of Ni metal almost coincides in both line shape and peak kinetic energy (KE) with the singles one. The former main line peak shows a KE shift of only 0.01 eV toward the lower KE and a very small asymmetric line shape change compared to the singles one. The asymmetric line shape change and the peak KE shift of the partial singles L 3 main line are very small. However, they are due to the variation with photoelectron KE in the branching ratio of the partial Auger decay width in the partial singles L 3 PES main line by the photoelectron KE dependent imaginary part of the shakeup self-energy. The L 3 PES main line of Ni metal measured in coincidence with the L 3 -VV ( 1 G) Auger electron spectroscopy (AES) main line peak is the partial singles one modulated by a spectral function R a of a fixed energy Auger electron analyzer so that it should show only a symmetric line narrowing by R a compared to the singles one. The L 3 PES main line peak of Ni metal measured in coincidence with the delocalized band-like L 3 -VV AES peak or not completely split-off (or not completely localized) L 3 -VV ( 3 F) AES peak, will show an asymmetric line narrowing and a KE shift compared to the singles one. Thus, the L 3 PES main line of Ni metal in coincidence with various parts of the L 3 -VV AES spectrum depends on which part of the L 3 -VV AES spectrum a fixed energy Auger electron analyzer is set. The experimental verification is in need

Investigation of Innervation Zone Shift with Continuous Dynamic Muscle Contraction

Directory of Open Access Journals (Sweden)

Ken Nishihara

2013-01-01

Full Text Available Innervation zone (IZ has been identified as the origin of action potential propagation in isometric contraction. However, IZ shifts with changes in muscle length during muscle activity. The IZ shift has been estimated using raw EMG signals. This study aimed to investigate the movement of IZ location during continuous dynamic muscle contraction, using a computer program. Subjects flexed their elbow joint as repetitive dynamic muscle contractions. EMG signals were recorded from the biceps brachii muscle using an eight-channel surface electrode array. Approximately 100 peaks from EMG signals were detected for each channel and summed to estimate the IZ location. For each subject, the estimated IZ locations were subtracted from the IZ location during isometric contractions with the elbow flexed at 90°. The results showed that the IZ moved significantly with elbow joint movement from 45° to 135°. However, IZ movement was biased with only a 3.9 mm IZ shift on average when the elbow angle was acute but a 16 mm IZ shift on average when it was obtuse. The movement of IZ location during continuous dynamic muscle contraction can be investigated using this signal processing procedure without subjective judgment.

Circular High-Q Resonating Isotropic Strain Sensors with Large Shift of Resonance Frequency under Stress

Directory of Open Access Journals (Sweden)

Hilmi Volkan Demir

2009-11-01

Full Text Available We present circular architecture bioimplant strain sensors that facilitate a strong resonance frequency shift with mechanical deformation. The clinical application area of these sensors is for in vivo assessment of bone fractures. Using a rectangular geometry, we obtain a resonance shift of 330 MHz for a single device and 170 MHz for its triplet configuration (with three side-by-side resonators on chip under an applied load of 3,920 N. Using the same device parameters with a circular isotropic architecture, we achieve a resonance frequency shift of 500 MHz for the single device and 260 MHz for its triplet configuration, demonstrating substantially increased sensitivity.

Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates.

Science.gov (United States)

Carmody, J Bryan; Seckeler, Michael D; Ballengee, Cortney R; Conaway, Mark; Jayakumar, K Anitha; Charlton, Jennifer R

2014-10-01

Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury. We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system. Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17). Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

The load shift potential of plug-in electric vehicles with different amounts of charging infrastructure

Science.gov (United States)

Gnann, Till; Klingler, Anna-Lena; Kühnbach, Matthias

2018-06-01

Plug-in electric vehicles are the currently favoured option to decarbonize the passenger car sector. However, a decarbonisation is only possible with electricity from renewable energies and plug-in electric vehicles might cause peak loads if they started to charge at the same time. Both these issues could be solved with coordinated load shifting (demand response). Previous studies analyzed this research question by focusing on private vehicles with domestic and work charging infrastructure. This study additionally includes the important early adopter group of commercial fleet vehicles and reflects the impact of domestic, commercial, work and public charging. For this purpose, two models are combined. In a comparison of three scenarios, we find that charging of commercial vehicles does not inflict evening load peaks in the same magnitude as purely domestic charging of private cars does. Also for private cars, charging at work occurs during the day and may reduce the necessity of load shifting while public charging plays a less important role in total charging demand as well as load shifting potential. Nonetheless, demand response reduces the system load by about 2.2 GW or 2.8% when domestic and work charging are considered compared to a scenario with only domestic charging.

Work zone simulator analysis : driver performance and acceptance of Missouri alternate lane shift configurations.

Science.gov (United States)

2017-01-13

The objective of this project is to evaluate MoDOTs alternate lane shift sign configuration for work zones. The single sign proposed by MoDOT provides the traveler with enough information to let them know that all lanes are available to shift arou...

Biofabrication of chitosan-silver composite SERS substrates enabling quantification of adenine by a spectroscopic shift

International Nuclear Information System (INIS)

Luo, X L; Bentley, W E; Buckhout-White, S; Rubloff, G W

2011-01-01

Surface-enhanced Raman scattering (SERS) has grown dramatically as an analytical tool for the sensitive and selective detection of molecules adsorbed on nano-roughened noble metal structures. Quantification with SERS based on signal intensity remains challenging due to the complicated fabrication process to obtain well-dispersed nanoparticles and well-ordered substrates. We report a new biofabrication strategy of SERS substrates that enable quantification through a newly discovered spectroscopic shift resulting from the chitosan-analyte interactions in solution. We demonstrate this phenomenon by the quantification of adenine, which is an essential part of the nucleic acid structure and a key component in pathways which generate signal molecules for bacterial communications. The SERS substrates were fabricated simply by sequential electrodeposition of chitosan on patterned gold electrodes and electroplating of a silver nitrate solution through the chitosan scaffold to form a chitosan-silver nanoparticle composite. Active SERS signals of adenine solutions were obtained in real time from the chitosan-silver composite substrates with a significant concentration-dependent spectroscopic shift. The Lorentzian curve fitting of the dominant peaks suggests the presence of two separate peaks with a concentration-dependent area percentage of the separated peaks. The chitosan-mediated composite SERS substrates can be easily biofabricated on predefined electrodes within microfluidic channels for real-time detection in microsystems.

Interaction of LED light with coinitiator-containing composite resins: effect of dual peaks.

Science.gov (United States)

Sim, Jae-Seong; Seol, Hyo-Joung; Park, Jeong-Kil; Garcia-Godoy, Franklin; Kim, Hyung-Il; Kwon, Yong Hoon

2012-10-01

Recently the colour stability of composite resins has been an issue due to the emphasis on the aesthetics of restored teeth. The purpose of the present study was to investigate how dual-peak LED units affect the polymerization of coinitiator-containing composite resins. Five composite resins [coinitiator-containing: Aelite LS Posterior (AL), Tetric EvoCeram (TE), and Vit-l-escence (VI); only CQ-containing: Grandio (GD) and Filtek Z350 (Z3)] were light cured using four different light-curing units (LCUs). Among them, Bluephase G2 (BP) and G-light (GL) were dual-peak LED LCUs. Microhardness, polymerization shrinkage, flexural, and compressive properties were measured. BP and GL had no consistent effect on the microhardness of AL, TE, and VI on the top and bottom surfaces of resin specimens. Among the specimens, AL and VI showed the least (9.86-10.41 μm) and greatest (17.58-19.21 μm) polymerization shrinkage, respectively. However, the effect of BP and GL on the shrinkage of specimens was not consistent. Among the specimens, GD showed the greatest flexural properties [strength (FS) and modulus (FM)] and TE showed the lowest flexural and compressive properties [strength (CS) and modulus (CM)]. In same resin product, maximum FS and CS differences due to the different LCUs were 10.3-21.0% and 3.6-9.2%, respectively. Furthermore, the influences of BP and GL on FS and CS were not consistent. The tested dual-peak LED LCUs had no consistent synergic effect on the polymerization of coinitiator-containing composite resins as compared with QTH and single-peak LED LCUs. The dual-peak LED LCUs achieve a similar degree of polymerization in coinitiator-composite resins as QTH and single-peak LED LCUs did. Choice of LCU does not appear to be a determinant of the light curing of coinitiator-composite resins. Copyright © 2012 Elsevier Ltd. All rights reserved.

Conditions and phase shift of fluid resonance in narrow gaps of bottom mounted caissons

Science.gov (United States)

Zhu, Da-tong; Wang, Xing-gang; Liu, Qing-jun

2017-12-01

This paper studies the viscid and inviscid fluid resonance in gaps of bottom mounted caissons on the basis of the plane wave hypothesis and full wave model. The theoretical analysis and the numerical results demonstrate that the condition for the appearance of fluid resonance in narrow gaps is kh=(2 n+1)π ( n=0, 1, 2, 3, …), rather than kh= nπ ( n=0, 1, 2, 3, …); the transmission peaks in viscid fluid are related to the resonance peaks in the gaps. k and h stand for the wave number and the gap length. The combination of the plane wave hypothesis or the full wave model with the local viscosity model can accurately determine the heights and the locations of the resonance peaks. The upper bound for the appearance of fluid resonance in gaps is 2 b/ Lreason for the phase shift of the resonance peaks is the inductive factors. The number of resonance peaks in the spectrum curve is dependent on the ratio of the gap length to the grating constant. The heights and the positions of the resonance peaks predicted by the present models agree well with the experimental data.

Single-electron charging effects and implications for tunneling measurements of the high-T/sub c/ superconductors

International Nuclear Information System (INIS)

Barner, J.B.; Honkanen, M.J.; Ruggiero, S.T.; Mullen, K.; Ben-Jacob, E.; Pelton, A.R.; Michigan Univ., Ann Arbor, MI

1989-01-01

The authors present a theory for the dynamics of two voltage-biased, ultra-small-capacitance tunnel junctions connected in series when one or more electrodes are superconducting and experiments performed on parallel arrays of such junctions. Using the semiclassical model, they find that the I-V characteristics display steps and therefore multiple peaks in dI/dV, corresponding to the time-average occupation of the interjunction region by integral numbers of electrons. The voltage at which the first step is located depends on the superconducting gap, Δ(T), and the capacitances of the junctions. The spacing between subsequent steps depends solely on the capacitances. They discuss electron tunneling results performed on metal/Al/sub 2/O/sub 3//2-10 nm-diameter metal particles/Al/sub 2/O/sub 3//metal junctions where this multiple-peak structure is observed. They present preliminary tunneling results in junctions employing Pb-particles, where they observe a shift of the peaks when the sample is cooled below T/sub c/ of Pb consistent with theory. Taken together, these results indicate that the multiple-peak structure commonly observed in tunneling data of high-T/sub c/ oxide superconductors can be explained in terms of charging effects in a material with a single superconducting gap. Finally, they discuss possible applications in a new type of transistor element

A Fiber Bragg Grating Interrogation System with Self-Adaption Threshold Peak Detection Algorithm.

Science.gov (United States)

Zhang, Weifang; Li, Yingwu; Jin, Bo; Ren, Feifei; Wang, Hongxun; Dai, Wei

2018-04-08

A Fiber Bragg Grating (FBG) interrogation system with a self-adaption threshold peak detection algorithm is proposed and experimentally demonstrated in this study. This system is composed of a field programmable gate array (FPGA) and advanced RISC machine (ARM) platform, tunable Fabry-Perot (F-P) filter and optical switch. To improve system resolution, the F-P filter was employed. As this filter is non-linear, this causes the shifting of central wavelengths with the deviation compensated by the parts of the circuit. Time-division multiplexing (TDM) of FBG sensors is achieved by an optical switch, with the system able to realize the combination of 256 FBG sensors. The wavelength scanning speed of 800 Hz can be achieved by a FPGA+ARM platform. In addition, a peak detection algorithm based on a self-adaption threshold is designed and the peak recognition rate is 100%. Experiments with different temperatures were conducted to demonstrate the effectiveness of the system. Four FBG sensors were examined in the thermal chamber without stress. When the temperature changed from 0 °C to 100 °C, the degree of linearity between central wavelengths and temperature was about 0.999 with the temperature sensitivity being 10 pm/°C. The static interrogation precision was able to reach 0.5 pm. Through the comparison of different peak detection algorithms and interrogation approaches, the system was verified to have an optimum comprehensive performance in terms of precision, capacity and speed.

A Fiber Bragg Grating Interrogation System with Self-Adaption Threshold Peak Detection Algorithm

Directory of Open Access Journals (Sweden)

Weifang Zhang

2018-04-01

Full Text Available A Fiber Bragg Grating (FBG interrogation system with a self-adaption threshold peak detection algorithm is proposed and experimentally demonstrated in this study. This system is composed of a field programmable gate array (FPGA and advanced RISC machine (ARM platform, tunable Fabry–Perot (F–P filter and optical switch. To improve system resolution, the F–P filter was employed. As this filter is non-linear, this causes the shifting of central wavelengths with the deviation compensated by the parts of the circuit. Time-division multiplexing (TDM of FBG sensors is achieved by an optical switch, with the system able to realize the combination of 256 FBG sensors. The wavelength scanning speed of 800 Hz can be achieved by a FPGA+ARM platform. In addition, a peak detection algorithm based on a self-adaption threshold is designed and the peak recognition rate is 100%. Experiments with different temperatures were conducted to demonstrate the effectiveness of the system. Four FBG sensors were examined in the thermal chamber without stress. When the temperature changed from 0 °C to 100 °C, the degree of linearity between central wavelengths and temperature was about 0.999 with the temperature sensitivity being 10 pm/°C. The static interrogation precision was able to reach 0.5 pm. Through the comparison of different peak detection algorithms and interrogation approaches, the system was verified to have an optimum comprehensive performance in terms of precision, capacity and speed.

Michelson interferometer based spatial phase shift shearography.

Science.gov (United States)

Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

2013-06-10

This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

29Si NMR Chemical Shift Calculation for Silicate Species by Gaussian Software

Science.gov (United States)

Azizi, S. N.; Rostami, A. A.; Godarzian, A.

2005-05-01

Hartree-Fock self-consistent-field (HF-SCF) theory and the Gauge-including atomic orbital (GIAO) methods are used in the calculation of 29Si NMR chemical shifts for ABOUT 90 units of 19 compounds of various silicate species of precursors for zeolites. Calculations have been performed at geometries optimized at the AM1 semi-empirical method. The GIAO-HF-SCF calculations were carried out with using three different basis sets: 6-31G*, 6-31+G** and 6-311+G(2d,p). To demonstrate the quality of the calculations the calculated chemical shifts, δ, were compared with the corresponding experimental values for the compounds in study. The results, especially with 6-31+g** are in excellent agreement with experimental values. The calculated chemical shifts, in practical point of view, appear to be accurate enough to aid in experimental peak assignments. The difference between the experimental and calculated 29Si chemical shift values not only depends on the Qn units but also it seems that basis set effects and the level of theory is more important. For the series of molecules studied here, the standard deviations and mean absolute errors for 29Si chemical shifts relative to TMS determined using Hartree--Fock 6-31+G** basis is nearly in all cases smaller than the errors for shifts determined using HF/6-311+G(2d,p).

Peak power ratio generator

Science.gov (United States)

Moyer, R.D.

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

What can we learn by computing 13Cα chemical shifts for X-ray protein models?

International Nuclear Information System (INIS)

Arnautova, Yelena A.; Vila, Jorge A.; Martin, Osvaldo A.; Scheraga, Harold A.

2009-01-01

The room-temperature X-ray structures of two proteins, solved at 1.8 and 1.9 Å resolution, are used to investigate whether a set of conformations, rather than a single X-ray structure, provides better agreement with both the X-ray data and the observed 13 C α chemical shifts in solution. The room-temperature X-ray structures of ubiquitin and of the RNA-binding domain of nonstructural protein 1 of influenza A virus solved at 1.8 and 1.9 Å resolution, respectively, were used to investigate whether a set of conformations rather than a single X-ray structure provides better agreement with both the X-ray data and the observed 13 C α chemical shifts in solution. For this purpose, a set of new conformations for each of these proteins was generated by fitting them to the experimental X-ray data deposited in the PDB. For each of the generated structures, which show R and R free factors similar to those of the deposited X-ray structure, the 13 C α chemical shifts of all residues in the sequence were computed at the DFT level of theory. The sets of conformations were then evaluated by their ability to reproduce the observed 13 C α chemical shifts by using the conformational average root-mean-square-deviation (ca-r.m.s.d.). For ubiquitin, the computed set of conformations is a better representation of the observed 13 C α chemical shifts in terms of the ca-r.m.s.d. than a single X-ray-derived structure. However, for the RNA-binding domain of nonstructural protein 1 of influenza A virus, consideration of an ensemble of conformations does not improve the agreement with the observed 13 C α chemical shifts. Whether an ensemble of conformations rather than any single structure is a more accurate representation of a protein structure in the crystal as well as of the observed 13 C α chemical shifts is determined by the dispersion of coordinates, in terms of the all-atom r.m.s.d. among the generated models; these generated models satisfy the experimental X-ray data with

Muon Knight shift and μ+ site in the monopnictide CeAs

International Nuclear Information System (INIS)

Schenck, A.; Amato, A.; Gygax, F.N.; Pinkpank, M.; Ott, H.R.

1997-01-01

The transverse field μSR-signal from μ + implanted in a CeAs single crystal shows a splitting into two components, displaying a positive and a negative Knight shift, respectively which both scale reasonably well with the magnetic bulk susceptibility above 10 K. The orientation dependence of the frequency shifts, measured at 15 K, is fully accounted for by the demagnetization field, implying an isotropic Knight shift, consistent with the μ + residing at the only interstitial site of high (cubic) symmetry, i.e., at the position (1/4,1/4,1/4). The occurrence of a split signal remains unexplained

System effects in sample self-stacking CZE: Single analyte peak splitting of salt-containing samples

Czech Academy of Sciences Publication Activity Database

Malá, Zdeňka; Gebauer, Petr; Boček, Petr

2009-01-01

Roč. 30, č. 5 (2009), s. 866-874 ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA AV ČR IAA400310609; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : CZE * peak splitting * self-stacking Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.077, year: 2009

Prolonged Instability Prior to a Regime Shift | Science ...

Science.gov (United States)

Regime shifts are generally defined as the point of ‘abrupt’ change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia. This manuscript explores various methods of assessing the transition between alternative states in an ecological system described by a long-term high-resolution paleoecological dataset.

A plant distribution shift: temperature, drought or past disturbance?

Directory of Open Access Journals (Sweden)

Dylan W Schwilk

Full Text Available Simple models of plant response to warming climates predict vegetation moving to cooler and/or wetter locations: in mountainous regions shifting upslope. However, species-specific responses to climate change are likely to be much more complex. We re-examined a recently reported vegetation shift in the Santa Rosa Mountains, California, to better understand the mechanisms behind the reported shift of a plant distribution upslope. We focused on five elevational zones near the center of the gradient that captured many of the reported shifts and which are dominated by fire-prone chaparral. Using growth rings, we determined that a major assumption of the previous work was wrong: past fire histories differed among elevations. To examine the potential effect that this difference might have on the reported upward shift, we focused on one species, Ceanothus greggii: a shrub that only recruits post-fire from a soil stored seedbank. For five elevations used in the prior study, we calculated time series of past per-capita mortality rates by counting growth rings on live and dead individuals. We tested three alternative hypotheses explaining the past patterns of mortality: 1 mortality increased over time consistent with climate warming, 2 mortality was correlated with drought indices, and 3 mortality peaked 40-50 years post fire at each site, consistent with self-thinning. We found that the sites were different ages since the last fire, and that the reported increase in the mean elevation of C. greggii was due to higher recent mortality at the lower elevations, which were younger sites. The time-series pattern of mortality was best explained by the self-thinning hypothesis and poorly explained by gradual warming or drought. At least for this species, the reported distribution shift appears to be an artifact of disturbance history and is not evidence of a climate warming effect.

Detection of a Reproducible, Single-Member Shift in Soil Bacterial Communities Exposed to Low Levels of Hydrogen▿

Science.gov (United States)

Osborne, Catherine A.; Peoples, Mark B.; Janssen, Peter H.

2010-01-01

Soil is exposed to hydrogen when symbiotic rhizobia in legume root nodules cannot recycle the hydrogen that is generated during nitrogen fixation. The hydrogen emitted is most likely taken up by free-living soil bacteria that use hydrogen as an energy source, though the bacteria that do this in situ remain unclear. In this study, we investigated the effect of hydrogen exposure on the bacteria of two different soils in a microcosm setup designed to simulate hydrogen-emitting root nodules. Although the size and overall composition of the soil bacterial community did not significantly alter after hydrogen exposure, one ribotype increased in relative abundance within each soil. This single-ribotype shift was identified by generating multiple terminal restriction fragment length polymorphism (T-RFLP) profiles of 16S rRNA genes from each soil sample, with gene sequence confirmation to identify terminal restriction fragments. The increased abundance of a single ribotype after hydrogen exposure, within an otherwise similar community, was found in replicate samples taken from each microcosm and was reproducible across replicate experiments. Similarly, only one member of the soil bacterial community increased in abundance in response to hydrogen exposure in soil surrounding the root nodules of field-grown soybean (Glycine max). The ribotypes that increased after hydrogen exposure in each soil system tested were all from known hydrogen-oxidizing lineages within the order Actinomycetales. We suggest that soil actinomycetes are important utilizers of hydrogen at relevant concentrations in soil and could be key contributors to soil's function as a sink in the global hydrogen cycle. PMID:20061453

Demand Side Management for the European Supergrid: Occupancy variances of European single-person households

International Nuclear Information System (INIS)

Torriti, Jacopo

2012-01-01

The prospect of a European Supergrid calls for research on aggregate electricity peak demand and Europe-wide Demand Side Management. No attempt has been made as yet to represent a time-related demand curve of residential electricity consumption at the European level. This article assesses how active occupancy levels of single-person households vary in single-person household in 15 European countries. It makes use of occupancy time-series data from the Harmonised European Time Use Survey database to build European occupancy curves; identify peak occupancy periods; construct time-related electricity demand curves for TV and video watching activities and assess occupancy variances of single-person households. - Highlights: ► Morning peak occupancies of European single households tale place between 7h30 and 7h40. ► Evening peaks take place between 20h10 and 20h20. ► TV and video activities during evening peaks make up about 3.1 GWh of European peak electricity load. ► Baseline and peak occupancy variances vary across countries. ► Baseline and peak occupancy variances can be used as input for Demand Side Management choices.

Electrical and proximity-magnetic effects induced quantum Goos–Hänchen shift on the surface of topological insulator

Energy Technology Data Exchange (ETDEWEB)

Kuai, Jian [School of Physics and Electronics, Yancheng Teachers College, Yancheng, 224002 Jiangsu (China); Da, H.X., E-mail: haixia8779@163.com [Electrical and Computer Engineering Department, National University of Singapore, 4 Engineering Drive 3, 117576 (Singapore)

2014-03-15

We use scattering matrix method to theoretically demonstrate that the quantum Goos–Hänchen shift of the surface on three-dimensional topological insulator coated by ferromagnetic strips is sensitive to the magnitude of ferromagnetic magnetization. The dependence of quantum Goos–Hänchen shift on magnetization and gate bias is investigated by performing station phase approach. It is found that quantum Goos–Hänchen shift is positive and large under the magnetic barrier but may be positive as well as negative values under the gate bias. Furthermore, the position of quantum Goos–Hänchen peak can also be modulated by the combination of gate bias and proximity magnetic effects. Our results indicate that topological insulators are another candidates to support quantum Goos–Hänchen shift. - Highlights: • Quantum Goos–Hänchen shift of the surface on three-dimensional topological insulators is first investigated. • The magnetization affects quantum Goos–Hänchen shift of the surface on three-dimensional topological insulators. • Quantum Goos–Hänchen shift of the surface on three-dimensional topological insulators can be manipulated by the gate voltages.

DC space-charge induced frequency up-shift in a quasi-optical gyrotron

International Nuclear Information System (INIS)

Alberti, S.; Tran, M.Q.; Tran, T.M.

1990-10-01

Recent experiments on a 100GHz quasi-optical gyrotron have shown that for a large resonator set-up the observed frequency up-shift between the starting current and a current of 10A corresponds to a shift of 4-5 longitudinal modes. In this Letter it is shown that the interpretation of this frequency up-shift should involve the current dependent electron beam voltage depression in the beam tunnel and the interaction region for both the single-mode and multi-mode time evolution codes. (author) 7 refs., 5 figs., 1 tab

Peak position differences observed during XPS sputter depth profiling of the SEI on lithiated and delithiated carbon-based anode material for Li-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Oswald, S., E-mail: s.oswald@ifw-dresden.de; Hoffmann, M.; Zier, M.

2017-04-15

Highlights: • In XPS measurements at graphite anodes for Li-ion batteries specific binding energy variations are observed for the SEI species. • The binding energy variations depend on the charging state of the graphite and not on surface charging effects. • Obviously the presence of elemental Li leads to a potential surface gradient in contact with surface layers. • The energy position of implanted Ar can be used as characteristic feature during sputter depth profiling experiments. - Abstract: The ability of delivering chemical information from peak shift phenomena has ever since made X-ray photoelectron spectroscopy (XPS) an ideal tool for material characterization in Li-ion batteries (LIB). Upon investigation, charging is inevitable as most of the chemical species involved are non-conducting. Thus, the binding energy (BE) scale must be corrected to allow an accurate interpretation of the results. This is usually done using the peak position of the ubiquitous surface carbon contamination detectable for all Li-ion battery relevant materials. We herein report on the occurrence of peak shift phenomena that can be observed when investigating surface layers on graphite anodes using sputter depth-profiling. These shifts, however, are not related to classical static electric charging, but are depending on the state of charge (lithiation) of the anode material. The observations presented are in agreement with previous findings on other Li-containing materials and are obviously caused by the presence of Li in its elemental state. As aging and failure mechanisms in LIBs are closely linked to electrolyte reaction products on electrode surfaces it is of high importance to draw the correct conclusions on their chemical origin from XP spectra. In order to avoid misinterpretation of the BE positions, implanted Ar can be used for identification of relevant peak positions and species involved in the phenomena observed.

Conformationally selective multidimensional chemical shift ranges in proteins from a PACSY database purged using intrinsic quality criteria

International Nuclear Information System (INIS)

Fritzsching, Keith J.; Hong, Mei; Schmidt-Rohr, Klaus

2016-01-01

We have determined refined multidimensional chemical shift ranges for intra-residue correlations ( 13 C– 13 C, 15 N– 13 C, etc.) in proteins, which can be used to gain type-assignment and/or secondary-structure information from experimental NMR spectra. The chemical-shift ranges are the result of a statistical analysis of the PACSY database of >3000 proteins with 3D structures (1,200,207 13 C chemical shifts and >3 million chemical shifts in total); these data were originally derived from the Biological Magnetic Resonance Data Bank. Using relatively simple non-parametric statistics to find peak maxima in the distributions of helix, sheet, coil and turn chemical shifts, and without the use of limited “hand-picked” data sets, we show that ∼94 % of the 13 C NMR data and almost all 15 N data are quite accurately referenced and assigned, with smaller standard deviations (0.2 and 0.8 ppm, respectively) than recognized previously. On the other hand, approximately 6 % of the 13 C chemical shift data in the PACSY database are shown to be clearly misreferenced, mostly by ca. −2.4 ppm. The removal of the misreferenced data and other outliers by this purging by intrinsic quality criteria (PIQC) allows for reliable identification of secondary maxima in the two-dimensional chemical-shift distributions already pre-separated by secondary structure. We demonstrate that some of these correspond to specific regions in the Ramachandran plot, including left-handed helix dihedral angles, reflect unusual hydrogen bonding, or are due to the influence of a following proline residue. With appropriate smoothing, significantly more tightly defined chemical shift ranges are obtained for each amino acid type in the different secondary structures. These chemical shift ranges, which may be defined at any statistical threshold, can be used for amino-acid type assignment and secondary-structure analysis of chemical shifts from intra-residue cross peaks by inspection or by using a

Conformationally selective multidimensional chemical shift ranges in proteins from a PACSY database purged using intrinsic quality criteria

Energy Technology Data Exchange (ETDEWEB)

Fritzsching, Keith J., E-mail: kfritzsc@brandeis.edu [Brandeis University, Department of Chemistry (United States); Hong, Mei [Massachusetts Institute of Technology, Department of Chemistry (United States); Schmidt-Rohr, Klaus, E-mail: srohr@brandeis.edu [Brandeis University, Department of Chemistry (United States)

2016-02-15

We have determined refined multidimensional chemical shift ranges for intra-residue correlations ({sup 13}C–{sup 13}C, {sup 15}N–{sup 13}C, etc.) in proteins, which can be used to gain type-assignment and/or secondary-structure information from experimental NMR spectra. The chemical-shift ranges are the result of a statistical analysis of the PACSY database of >3000 proteins with 3D structures (1,200,207 {sup 13}C chemical shifts and >3 million chemical shifts in total); these data were originally derived from the Biological Magnetic Resonance Data Bank. Using relatively simple non-parametric statistics to find peak maxima in the distributions of helix, sheet, coil and turn chemical shifts, and without the use of limited “hand-picked” data sets, we show that ∼94 % of the {sup 13}C NMR data and almost all {sup 15}N data are quite accurately referenced and assigned, with smaller standard deviations (0.2 and 0.8 ppm, respectively) than recognized previously. On the other hand, approximately 6 % of the {sup 13}C chemical shift data in the PACSY database are shown to be clearly misreferenced, mostly by ca. −2.4 ppm. The removal of the misreferenced data and other outliers by this purging by intrinsic quality criteria (PIQC) allows for reliable identification of secondary maxima in the two-dimensional chemical-shift distributions already pre-separated by secondary structure. We demonstrate that some of these correspond to specific regions in the Ramachandran plot, including left-handed helix dihedral angles, reflect unusual hydrogen bonding, or are due to the influence of a following proline residue. With appropriate smoothing, significantly more tightly defined chemical shift ranges are obtained for each amino acid type in the different secondary structures. These chemical shift ranges, which may be defined at any statistical threshold, can be used for amino-acid type assignment and secondary-structure analysis of chemical shifts from intra

A new plastic scintillator with large Stokes shift

International Nuclear Information System (INIS)

Destruel, P.; Taufer, M.

1989-01-01

We have developed a new plastic scintillator with the novel characteristic of highly localized light emission; scintillation and wavelength shifting take place within a few tens of micrometers of the primary ionization. The new scintillator consists of a scintillating polymer base [polyvinyl toluene (PVT) or polystyrene (PS)] doped with a single wavelength shifter, 1-phenyl-3-mesityl-2-pyrazoline (PMP), which has an exceptionally large Stokes shift and therefore a comparatively small self-absorption of its emitted light. In other characteristics (e.g. scintillation efficiency and decay time) the performance of the new scintillator is similar to a good quality commercial plastic scintillator such as NE110. (orig.)

Electronic state and photoionization cross section of a single dopant in GaN/InGaN core/shell quantum dot under magnetic field and hydrostatic pressure

Science.gov (United States)

Aouami, A. El; Feddi, E.; Talbi, A.; Dujardin, F.; Duque, C. A.

2018-06-01

In this study, we have investigated the simultaneous influence of magnetic field combined to the hydrostatic pressure and the geometrical confinement on the behavior of a single dopant confined in GaN/InGaN core/shell quantum dots. Within the scheme of the effective-mass approximation, the eigenvalues equation has solved by using the variational method with one-parameter trial wavefunctions. Variation of the ground state binding energy of the single dopant is determined according to the magnetic field and hydrostatic pressure for several dimensions of the heterostructure. The results show that the binding energy is strongly dependent on the core/shell sizes, the magnetic field, and the hydrostatic pressure. The analysis of the photoionization cross section, corresponding to optical transitions associated to the first donor energy level and the conduction band, shows clearly that the reduction of the dot dimensions and/or the simultaneous influences of applied magnetic field, combined to the hydrostatic pressure strength, cause a shift in resonance peaks towards the higher energies with important variations in the magnitude of the resonant peaks.

Strong reduction of spectral heterogeneity in gold bipyramids for single-particle and single-molecule plasmon sensing.

Science.gov (United States)

Peters, S M E; Verheijen, M A; Prins, M W J; Zijlstra, P

2016-01-15

Single metal nanoparticles are attractive biomolecular sensors. Binding of analyte to a functional particle results in a plasmon shift that can be conveniently monitored in a far-field optical microscope. Heterogeneities in spectral properties of individual particles in an ensemble affect the reliability of a single-particle plasmon sensor, especially when plasmon shifts are monitored in real-time using a fixed irradiation wavelength. We compare the spectral heterogeneity of different plasmon sensor geometries (gold nanospheres, nanorods, and bipyramids) and correlate this to their size and aspect-ratio dispersion. We show that gold bipyramids exhibit a strongly reduced heterogeneity in aspect ratio and plasmon wavelength compared to commonly used gold nanorods. We show that this translates into a significantly improved homogeneity of the response to molecular binding without compromising single-molecule sensitivity.

Morphology, surface roughness, electron inelastic and quasi-elastic scattering in elastic peak electron spectroscopy of polymers

International Nuclear Information System (INIS)

Lesiak, B.; Kosinski, A.; Nowakowski, R.; Koever, L.; Toth, J.; Varga, D.; Cserny, I.; Sulyok, A.; Gergely, G.

2006-01-01

Complete text of publication follows. Elastic peak electron spectroscopy (EPES) deals with the interaction of electrons with atoms of a solid surface, studying the distribution of electrons backscattered elastically. The nearest vicinity of the elastic peak, (low kinetic energy region) reflects both, electron inelastic and quasi-elastic processes. The incident electrons produce surface excitations, inducing surface plasmons with the corresponding loss peaks separated by 1 - 20 eV energy from the elastic peak. Quasi-elastic losses result from the recoil of scattering atoms of different atomic number, Z. The respective energy shift and Doppler broadening of the elastic peak depend on Z, the primary electron energy, E, and the measurement geometry. Quantitative surface analytical application of EPES, such as determination of parameters describing electron transport, requires a comparison of experimental data with corresponding data derived from Monte Carlo (MC) simulation. Several problems occur in EPES studies of polymers. The intensity of elastic peak, considered in quantitative surface analysis, is influenced by both, the inelastic and quasi-elastic scattering processes (especially for hydrogen scattering atoms and primary electron energy above 1000 eV). An additional factor affecting the elastic peak intensity is the surface morphology and roughness. The present work compares the effect of these factors on the elastic peak intensity for selected polymers (polyethylene, polyaniline and polythiophenes). X-ray photoelectron spectroscopy (XPS) and helium pycnometry are applied for deriving the surface atomic composition and the bulk density, while scanning electron microscopy (SEM) and atomic force microscopy (AFM) for determining surface morphology and roughness. According to presented results, the influence of surface morphology and roughness is larger than those of surface excitations or recoil of hydrogen atoms. The component due to recoil of hydrogen atoms can be

High-Performance Single Nanowire Tunnel Diodes

DEFF Research Database (Denmark)

Wallentin, Jesper; Persson, Johan Mikael; Wagner, Jakob Birkedal

2010-01-01

We demonstrate single nanowire tunnel diodes with room temperature peak current densities of up to 329 A/cm(2). Despite the large surface to volume ratio of the type-II InP-GaAs axial heterostructure nanowires, we measure peak to valley current ratios (PVCR) of up to 8.2 at room temperature and 27...

PRESSURE SHIFT AND GRAVITATIONAL REDSHIFT OF BALMER LINES IN WHITE DWARFS: REDISCUSSION

Energy Technology Data Exchange (ETDEWEB)

Halenka, Jacek; Olchawa, Wieslaw [Institute of Physics, University of Opole, ul. Oleska 48, 45-052, Opole (Poland); Madej, Jerzy [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Grabowski, Boleslaw, E-mail: halenka@uni.opole.pl, E-mail: wolch@uni.opole.pl, E-mail: jm@astrouw.edu.pl, E-mail: bgrab@uni.opole.pl [Wroclaw School of Information Technology WWSIS “Horyzont,” ul. Wejherowska 28, 54-239 Wroclaw (Poland)

2015-08-01

The Stark-induced shift and asymmetry, the so-called pressure shift (PS) of H{sub α} and H{sub β} Balmer lines in spectra of DA white dwarfs (WDs), have been examined in detail as masking effects in measurements of the gravitational redshift in WDs. The results are compared with our earlier ones from a quarter of a century ago. In these earlier papers, the standard, symmetrical Stark line profiles, as a dominant constituent of the Balmer line profiles but shifted as a whole by the PS effect, were applied to all spectrally active layers of the WD atmosphere. At present, in each of the WD layers, the Stark line profiles (especially of H{sub β}) are inherently asymmetrical and shifted due to the effects of strong inhomogeneity of the perturbing fields in plasma. To calculate the Stark line profiles in successive layers of the WD atmosphere we used the modified Full Computer Simulation Method, able to take adequately into account the complexity of local elementary quantum processes in plasma. In the case of the H{sub α} line, the present value of Stark-induced shift of the synthetic H{sub α} line profile is about half the previous one and it is negligible in comparison with the gravitational redshift. In the case of the H{sub β} line, the present value of Stark-induced shift of the synthetic H{sub β} line profile is about twice the previous one. The source of this extra shift is the asymmetry of H{sub β} peaks.

Identification of squid species by melting temperature shifts on fluorescence melting curve analysis (FMCA) using single dual-labeled probe

Science.gov (United States)

Koh, Eunjung; Song, Ha Jeong; Kwon, Na Young; Kim, Gi Won; Lee, Kwang Ho; Jo, Soyeon; Park, Sujin; Park, Jihyun; Park, Eun Kyeong; Hwang, Seung Yong

2017-06-01

Real time PCR is a standard method for identification of species. One of limitations of the qPCR is that there would be false-positive result due to mismatched hybridization between target sequence and probe depending on the annealing temperature in the PCR condition. As an alternative, fluorescence melting curve analysis (FMCA) could be applied for species identification. FMCA is based on a dual-labeled probe. Even with subtle difference of target sequence, there are visible melting temperature (Tm) shift. One of FMCA applications is distinguishing organisms distributed and consumed globally as popular food ingredients. Their prices are set by species or country of origin. However, counterfeiting or distributing them without any verification procedure are becoming social problems and threatening food safety. Besides distinguishing them in naked eye is very difficult and almost impossible in any processed form. Therefore, it is necessary to identify species in molecular level. In this research three species of squids which have 1-2 base pair differences each are selected as samples since they have the same issue. We designed a probe which perfectly matches with one species and the others mismatches 2 and 1 base pair respectively and labeled with fluorophore and quencher. In an experiment with a single probe, we successfully distinguished them by Tm shift depending on the difference of base pair. By combining FMCA and qPCR chip, smaller-scale assay with higher sensitivity and resolution could be possible, andc furthermore, enabling results analysis with smart phone would realize point-of-care testing (POCT).

Evidence for a single hydrogen molecule connected by an atomic chain

DEFF Research Database (Denmark)

Kiguchi, M.; Stadler, Robert; Bækgaard, Iben Sig Buur

2007-01-01

Stable, single-molecule conducting-bridge configurations are typically identified from peak structures in a conductance histogram. In previous work on Pt with H-2 at cryogenic temperatures it has been shown that a peak near 1G(0) identifies a single-molecule Pt-H-2-Pt bridge. The histogram shows...

Multiparametric fat-water separation method for fast chemical-shift imaging guidance of thermal therapies.

Science.gov (United States)

Lin, Jonathan S; Hwang, Ken-Pin; Jackson, Edward F; Hazle, John D; Stafford, R Jason; Taylor, Brian A

2013-10-01

A k-means-based classification algorithm is investigated to assess suitability for rapidly separating and classifying fat/water spectral peaks from a fast chemical shift imaging technique for magnetic resonance temperature imaging. Algorithm testing is performed in simulated mathematical phantoms and agar gel phantoms containing mixed fat/water regions. Proton resonance frequencies (PRFs), apparent spin-spin relaxation (T2*) times, and T1-weighted (T1-W) amplitude values were calculated for each voxel using a single-peak autoregressive moving average (ARMA) signal model. These parameters were then used as criteria for k-means sorting, with the results used to determine PRF ranges of each chemical species cluster for further classification. To detect the presence of secondary chemical species, spectral parameters were recalculated when needed using a two-peak ARMA signal model during the subsequent classification steps. Mathematical phantom simulations involved the modulation of signal-to-noise ratios (SNR), maximum PRF shift (MPS) values, analysis window sizes, and frequency expansion factor sizes in order to characterize the algorithm performance across a variety of conditions. In agar, images were collected on a 1.5T clinical MR scanner using acquisition parameters close to simulation, and algorithm performance was assessed by comparing classification results to manually segmented maps of the fat/water regions. Performance was characterized quantitatively using the Dice Similarity Coefficient (DSC), sensitivity, and specificity. The simulated mathematical phantom experiments demonstrated good fat/water separation depending on conditions, specifically high SNR, moderate MPS value, small analysis window size, and low but nonzero frequency expansion factor size. Physical phantom results demonstrated good identification for both water (0.997 ± 0.001, 0.999 ± 0.001, and 0.986 ± 0.001 for DSC, sensitivity, and specificity, respectively) and fat (0.763 ± 0.006, 0

The influence of applied internal and external rotation on the pivot shift phenomenon.

Science.gov (United States)

Kopf, Sebastian; Musahl, Volker; Perka, Carsten; Kauert, Ralf; Hoburg, Arnd; Becker, Roland

2017-04-01

The pivot shift test is performed in different techniques and the rotation of the tibia seems to have a significant impact on the amount of the pivot shift phenomenon. It has been hypothesised that external rotation will increase the phenomenon due to less tension at the iliotibial band in knee extension. Twenty-four patients with unilateral anterior cruciate ligament insufficiency were included prospectively. The pivot shift test was performed bilaterally in internal and external tibial rotation under general anaesthesia. Knee motion was captured using a femoral and a tibial inertial sensor. The difference between positive and negative peak values in Euclidean norm of acceleration was calculated to evaluate the amount of the pivot shift phenomenon. The pivot shift phenomenon was significantly increased in patients with ACL insufficiency when the test was performed in external [mean 5.2 ms - 2 (95% CI 4.3-6.0)] compared to internal tibial rotation [mean 4.4 ms - 2 (95% CI 3.5-5.4)] (p = 0.002). In healthy, contralateral knees did not show any difference between external [mean 4.0 ms - 2 (95% CI 3.3-4.7)] and internal tibial rotation [mean 4.0 ms - 2 (95% CI 3.4-4.6)] (ns). The pivot shift phenomenon was increased with external rotation in ACL-insufficient knees, and therefore, one should perform the pivot shift test, rather, in external rotation to easily evoke the, sometimes difficult to detect, pivot shift phenomenon. I (diagnostic study).

Exciton diamagnetic shift and optical properties in CdSe nanocrystal quantum dots in magnetic fields

Science.gov (United States)

Wu, Shudong; Cheng, Liwen

2018-04-01

The magnetic field dependence of the optical properties of CdSe nanocrystal quantum dots (NQDs) is investigated theoretically using a perturbation method within the effective-mass approximation. The results show that the magnetic field lifts the degeneracy of the electron (hole) states. A blue-shift in the absorption spectra of m ≥ 0 exciton states is observed while the absorption peak of m attributed to the interplay of the orbital Zeeman effect and the additive confinement induced by the magnetic field. The excitonic absorption coefficient is almost independent of B in the strong confinement regime. The applied magnetic field causes the splitting of degenerated exciton states, resulting in the new absorption peaks. Based on the first-order perturbation theory, we propose the analytical expressions for the exciton binding energy, exciton transition energy and exciton diamagnetic shift of 1s, 1p-1, 1p0, 1p1, 1d-2, 1d-1, 1d0, 1d1, 1d2 and 2s exciton states on the applied magnetic field in the strong confinement regime.

Peak capacity and peak capacity per unit time in capillary and microchip zone electrophoresis.

Science.gov (United States)

Foley, Joe P; Blackney, Donna M; Ennis, Erin J

2017-11-10

The origins of the peak capacity concept are described and the important contributions to the development of that concept in chromatography and electrophoresis are reviewed. Whereas numerous quantitative expressions have been reported for one- and two-dimensional separations, most are focused on chromatographic separations and few, if any, quantitative unbiased expressions have been developed for capillary or microchip zone electrophoresis. Making the common assumption that longitudinal diffusion is the predominant source of zone broadening in capillary electrophoresis, analytical expressions for the peak capacity are derived, first in terms of migration time, diffusion coefficient, migration distance, and desired resolution, and then in terms of the remaining underlying fundamental parameters (electric field, electroosmotic and electrophoretic mobilities) that determine the migration time. The latter expressions clearly illustrate the direct square root dependence of peak capacity on electric field and migration distance and the inverse square root dependence on solute diffusion coefficient. Conditions that result in a high peak capacity will result in a low peak capacity per unit time and vice-versa. For a given symmetrical range of relative electrophoretic mobilities for co- and counter-electroosmotic species (cations and anions), the peak capacity increases with the square root of the electric field even as the temporal window narrows considerably, resulting in a significant reduction in analysis time. Over a broad relative electrophoretic mobility interval [-0.9, 0.9], an approximately two-fold greater amount of peak capacity can be generated for counter-electroosmotic species although it takes about five-fold longer to do so, consistent with the well-known bias in migration time and resolving power for co- and counter-electroosmotic species. The optimum lower bound of the relative electrophoretic mobility interval [μ r,Z , μ r,A ] that provides the maximum

The effects of Si-doped prelayers on the optical properties of InGaN/GaN single quantum well structures

Energy Technology Data Exchange (ETDEWEB)

Davies, M. J., E-mail: Matthew.Davies-2@Manchester.ac.uk; Dawson, P. [School of Physics and Astronomy, Photon Science Institute, University of Manchester, Manchester M13 9PL (United Kingdom); Massabuau, F. C.-P.; Oliver, R. A.; Kappers, M. J.; Humphreys, C. J. [Department of Material Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2014-09-01

In this paper, we report on the effects of including Si-doped (In)GaN prelayers on the low temperature optical properties of a blue-light emitting InGaN/GaN single quantum well. We observed a large blue shift of the photoluminescence peak emission energy and significant increases in the radiative recombination rate for the quantum well structures that incorporated Si-doped prelayers. Simulations of the variation of the conduction and valence band energies show that a strong modification of the band profile occurs for the quantum wells on Si-doped prelayers due to an increase in strength of the surface polarization field. The enhanced surface polarization field opposes the built-in field across the quantum well and thus reduces this built-in electric field. This reduction of the electric field across the quantum well reduces the Quantum Confined Stark Effect and is responsible for the observed blue shift and the change in the recombination dynamics.

Electrostatic Origin of the Red Solvatochromic Shift of DFHBDI in RNA Spinach.

Science.gov (United States)

Bose, Samik; Chakrabarty, Suman; Ghosh, Debashree

2017-05-11

Interactions with the environment tune the spectral properties of biological chromophores, e.g., fluorescent proteins. Understanding the relative contribution of the various types of noncovalent interactions in the spectral shifts can provide rational design principles toward developing new fluorescent probes. In this work, we investigate the origin of the red shift in the absorption spectra of the difluoro hydroxybenzylidene dimethyl imidazolinone (DFHBDI) chromophore in RNA spinach as compared to the aqueous solution. We systematically decompose the effects of various components of interactions, namely, stacking, hydrogen bonding, and long-range electrostatics, in order to elucidate the relative role of these interactions in the observed spectral behavior. We find that the absorption peak of DFHBDI is red-shifted by ∼0.35 eV in RNA relative to the aqueous solution. Earlier proposals from Huang and co-workers have implicated the stacking interactions between DFHBDI and nucleic acid bases to be the driving force behind the observed red shift. In contrast, our findings reveal that the long-range electrostatic interactions between DFHBDI and negatively charged RNA make the most significant contribution. Moreover, we notice that the opposing electrostatic fields due to the RNA backbone and the polarized water molecules around the RNA give rise to the resultant red shift. Our results emphasize the effect of strong heterogeneity in the various environmental factors that might be competing with each other.

Polarized phase shift mask: concept, design, and potential advantages to photolithography process and physical design

Science.gov (United States)

Wang, Ruoping; Grobman, Warren D.; Reich, Alfred J.; Thompson, Matthew A.

2002-03-01

In this paper we introduce the concept and design of a novel phase shift mask technology, Polarized Phase Shift Mask (P:PSM). The P:PSM technology utilizes non-interference between orthogonally polarized light sources to avoid undesired destructive interference seen in conventional two-phase shift mask technology. Hence P:PSM solves the well-known 'phase edge' or 'phase conflict' problem. By obviating the 2nd exposure and 2nd mask in current Complementary Phase Shift Mask (C:PSM) technology, this single mask/single exposure technology offers significant advantages towards photolithography process as well as pattern design. We use examples of typical design and process difficulties associated with the C:PSM technology to illustrate the advantages of the P:PSM technology. We present preliminary aerial image simulation results that support the potential of this new reticle technology for enhanced design flexibility. We also propose possible mask structures and manufacturing methods for building a P:PSM.

The collective Lamb shift in nuclear γ-ray superradiance

International Nuclear Information System (INIS)

Röhlsberger, Ralf

2012-01-01

The electromagnetic transitions of Mössbauer nuclei provide almost ideal two-level systems to transfer quantum optical concepts into the regime of hard x-rays. If many identical atoms collectively interact with a resonant radiation field, one observes (quantum) optical properties that are strongly different from those of a single atom. The most prominent effect is the broadening of the resonance line known as collective enhancement, resulting from multiple scattering of real photons within the atomic ensemble. On the other hand, the exchange of virtual photons within the ensemble leads to a tiny energy shift of the resonance line, the collective Lamb shift, that remained experimentally elusive for a long time after its prediction. Here we illustrate how highly brilliant synchrotron radiation allows one to prepare superradiant states of excited Mössbauer nuclei, an important condition for observation of the collective Lamb shift.

Phase-shifted Bragg grating inscription in PMMA microstructured POF using 248 nm UV radiation

DEFF Research Database (Denmark)

Pereira, L.; Pospori, A.; Antunes, Paulo

2017-01-01

In this work we experimentally validate and characterize the first phase-shifted polymer optical fiber Bragg gratings (PS-POFBGs) produced using a single pulse from a 248 nm krypton fluoride laser. A single-mode poly (methyl methacrylate) optical fiber with a core doped with benzyl dimethyl ketal...... for photosensitivity improvement was used. A uniform phase mask customized for 850 nm grating inscription was used to inscribe these Bragg structures. The phase shift defect was created directly during the grating inscription process by placing a narrow blocking aperture in the center of the UV beam. The produced high...

Evaluation of the impact of peak description on the quantitative capabilities of comprehensive two-dimensional liquid chromatography.

Science.gov (United States)

Place, Benjamin J; Morris, Mallory J; Phillips, Melissa M; Sander, Lane C; Rimmer, Catherine A

2014-11-14

Comprehensive, two-dimensional liquid chromatography (LC × LC) is a powerful technique for the separation of complex mixtures. Most studies using LC × LC are focused on qualitative efforts, such as increasing peak capacity. The present study examined the use of LC × LC-UV/vis for the separation and quantitation of polycyclic aromatic hydrocarbons (PAHs). More specifically, this study evaluated the impact of different peak integration approaches on the quantitative performance of the LC × LC method. For well-resolved three-dimensional peaks, parameters such as baseline definition, peak base shape, and peak width determination did not have a significant impact on accuracy and precision. For less-resolved peaks, a dropped baseline and the summation of all slices in the peak improved the accuracy and precision of the integration methods. The computational approaches to three-dimensional peak integration are provided, including fully descriptive, select slice, and summed heights integration methods, each with its own strengths and weaknesses. Overall, the integration methods presented quantify each of the PAHs within acceptable precision and accuracy ranges and have comparable performance to that of single dimension liquid chromatography. Published by Elsevier B.V.

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

Energy Technology Data Exchange (ETDEWEB)

Cutshall, N H; Larsen, I L [Oak Ridge National Lab., TN (USA)

1980-12-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented.

A stochastic method for battery sizing with uninterruptible-power and demand shift capabilities in PV (photovoltaic) systems

International Nuclear Information System (INIS)

Tan, Chee Wei; Green, Tim C.; Hernandez-Aramburo, Carlos A.

2010-01-01

This paper presents a stochastic simulation using Monte Carlo technique to size a battery to meet dual objectives of demand shift at peak electricity cost times and outage protection in BIPV (building integrated photovoltaic) systems. Both functions require battery storage and the sizing of battery using numerical optimization is popularly used. However, the weather conditions, outage events and demand peaks are not deterministic in nature. Therefore, the sizing of battery storage capacity should also be based on a probabilistic approach. The Monte Carlo simulation is a rigorous method to sizing BIPV system as it takes into account a real building load profiles, the weather information and the local historical outage distribution. The simulation is split into seasonal basis for the analysis of demand shifting and outage events in order to match the seasonal weather conditions and load profiles. Five configurations of PV (photovoltaic) are assessed that cover different areas and orientations. The simulation output includes the predicted PV energy yield, the amount of energy required for demand management and outage event. Therefore, consumers can base sizing decisions on the historical data and local risk of outage statistics and the success rate of meeting the demand shift required. Finally, the economic evaluations together with the sensitivity analysis and the assessment of customers' outage cost are discussed.

Thermoluminescence of SrAl_2O_4:Eu"2"+, Dy"3"+: dosimetric characteristics and evidence of glow-peak collocation

International Nuclear Information System (INIS)

Chithambo, M.L.

2016-01-01

The thermoluminescence of SrAl_2O_4:Eu"2"+, Dy"3"+ consists of collocated peaks whereby a dominant component subsumes subsidiary ones to such an extent that they appear as one; Qualitative and quantitative analysis of such cases will be described with suitable illustrative examples. The general features and qualitative kinetics properties of thermoluminescence from SrAl_2O_4:Eu"2"+, Dy"3"+ is reported. Measurements using X-ray excited optical luminescence show that stimulated luminescence from SrAl_2O_4:Eu"2"+, Dy"3"+ has two prominent emission bands, one at 475 nm and a more intense one near 575 nm, studied in this work. There are also weaker intensity emissions at 405, 510, 600 and 660 nm. The natural thermoluminescence measured at 1°C s"-"1 shows three peaks at 74, 170 and 340°C whereas 20 Gy beta-irradiation produces TL dominated by a single peak at 34°C. Analysis of this peak for its order of kinetics produces somewhat inconclusive results. The results of the partial heating procedure T_m - T_s_t_o_p are consistent with both first and second-order kinetics. On the other hand, the position of the peak is independent of dose for several ranges of doses implying that the apparently single peak consists of multiple first-order peaks. Complementary investigations using the fractional glow technique, resolution by isothermal heating and the effect of fading on the peak show that the glow-curve of SrAl_2O_4:Eu"2"+, Dy"3"+ comprises closely collocated thermoluminescence peaks. The implication of such complexity on kinetic analysis on this material and others that share this feature will be discussed. (author)

Peaking-factor of PWR

International Nuclear Information System (INIS)

Morioka, Noboru; Kato, Yasuji; Yokoi, M.

1975-01-01

Output peaking factor often plays an important role in the safety and operation of nuclear reactors. The meaning of the peaking factor of PWRs is categorized into two features or the peaking factor in core (FQ-core) and the peaking factor on the basis of accident analysis (or FQ-limit). FQ-core is the actual peaking factor realized in nuclear core at the time of normal operation, and FQ-limit should be evaluated from loss of coolant accident and other abnormal conditions. If FQ-core is lower than FQ-limit, the reactor may be operated at full load, but if FQ-core is larger than FQ-limit, reactor output should be controlled lower than FQ-limit. FQ-core has two kinds of values, or the one on the basis of nuclear design, and the other actually measured in reactor operation. The first FQ-core should be named as FQ-core-design and the latter as FQ-core-measured. The numerical evaluation of FQ-core-design is as follows; FQ-core-design of three-dimensions is synthesized with FQ-core horizontal value (X-Y) and FQ-core vertical value, the former one is calculated with ASSY-CORE code, and the latter one with one dimensional diffusion code. For the evaluation of FQ-core-measured, on-site data observation from nuclear reactor instrumentation or off-site data observation is used. (Iwase, T.)

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

International Nuclear Information System (INIS)

Cutshall, N.H.; Larsen, I.L.

1980-01-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented. (orig.)

Peak Shift in Pigeon and Human Categorisation

OpenAIRE

Aitken, Michael R. F.

1996-01-01

In a series of experiments, both pigeon and human subjects were trained to categorise two groups of confusable stimuli, with each category being made up of distortions of a ‘Prototype’. Once the subjects had successfully learned to categorise the training stimuli, they were tested on their responding to a variety of previously unseen stimuli: these were distortions of the Prototypes towards (‘Closer’ exemplars), or away from (‘Further’ exemplars), the other category, and the Prototypes thems...

WE-EF-207-06: Dedicated Cone-Beam Breast CT with Laterally-Shifted Detector: Monte Carlo Evaluation of X-Ray Scatter Distribution and Scatter-To-Primary Ratio

International Nuclear Information System (INIS)

Shi, L; Vedantham, S; Karellas, A

2015-01-01

Purpose: To determine the spatial distribution of x-ray scatter and scatter-to-primary ratio (SPR) in projections during cone-beam breast CT (CBBCT) with laterally-shifted detector that results in coronal (fan-angle) truncation. Methods: We hypothesized that CBBCT with coronal truncation would lower SPR due to reduction in irradiated breast volume, and that the location of maximum x-ray scatter fluence (scatter-peak) in the detector plane can be determined from the ratio of irradiated-to-total breast volume, breast dimensions and system geometry. Monte Carlo simulations (GEANT4) reflecting a prototype CBBCT system were used to record the position-dependent primary and scatter x-ray photon fluence incident on the detector without coronal truncation (full fan-angle, 2f=24-degrees) and with coronal truncation (fan-angle, f+ f=12+2.7-degrees). Semi-ellipsoidal breasts (10/14/18-cm diameter, chest-wall to nipple length: 0.75xdiameter, 2%/14%/100% fibroglandular content) aligned with the axis-of-rotation (AOR) were modeled. Mono-energy photons were simulated and weighted for 2 spectra (49kVp, 1.4-mm Al HVL; 60kVp, 3.76-mm Al HVL). In addition to SPR, the scatter maps were analyzed to identify the location of the scatter-peak. Results: For CBBCT without fan-angle truncation, the scatter-peaks were aligned with the projection of the AOR onto the detector for all breasts. With truncated fan-beam, the scatter-peaks were laterally-shifted from the projection of the AOR along the fan-angle direction by 14/38/70-pixels for 10/14/18-cm diameter breasts. The corresponding theoretical shifts were 14.8/39.7/68-pixels (p=0.47, 2-tailed paired-ratio t-test). Along the cone-angle, the shift in scatter-peaks between truncated and full-fan angle CBBCT were 2/2/4 -pixels for 10/14/18-cm diameter breasts. CBBCT with fan-angle truncation reduced SPR by 14/22/28% for 10/14/18-cm diameter breasts. 60kVp reduced SPR by 21–25% compared to 49kVp. Peak SPR for CBBCT with fan-angle truncation

Evaluation of different time domain peak models using extreme learning machine-based peak detection for EEG signal.

Science.gov (United States)

Adam, Asrul; Ibrahim, Zuwairie; Mokhtar, Norrima; Shapiai, Mohd Ibrahim; Cumming, Paul; Mubin, Marizan

2016-01-01

Various peak models have been introduced to detect and analyze peaks in the time domain analysis of electroencephalogram (EEG) signals. In general, peak model in the time domain analysis consists of a set of signal parameters, such as amplitude, width, and slope. Models including those proposed by Dumpala, Acir, Liu, and Dingle are routinely used to detect peaks in EEG signals acquired in clinical studies of epilepsy or eye blink. The optimal peak model is the most reliable peak detection performance in a particular application. A fair measure of performance of different models requires a common and unbiased platform. In this study, we evaluate the performance of the four different peak models using the extreme learning machine (ELM)-based peak detection algorithm. We found that the Dingle model gave the best performance, with 72 % accuracy in the analysis of real EEG data. Statistical analysis conferred that the Dingle model afforded significantly better mean testing accuracy than did the Acir and Liu models, which were in the range 37-52 %. Meanwhile, the Dingle model has no significant difference compared to Dumpala model.

3D atom microscopy in the presence of Doppler shift

Science.gov (United States)

Rahmatullah; Chuang, You-Lin; Lee, Ray-Kuang; Qamar, Sajid

2018-03-01

The interaction of hot atoms with laser fields produces a Doppler shift, which can severely affect the precise spatial measurement of an atom. We suggest an experimentally realizable scheme to address this issue in the three-dimensional position measurement of a single atom in vapors of rubidium atoms. A three-level Λ-type atom-field configuration is considered where a moving atom interacts with three orthogonal standing-wave laser fields and spatial information of the atom in 3D space is obtained via an upper-level population using a weak probe laser field. The atom moves with velocity v along the probe laser field, and due to the Doppler broadening the precision of the spatial information deteriorates significantly. It is found that via a microwave field, precision in the position measurement of a single hot rubidium atom can be attained, overcoming the limitation posed by the Doppler shift.

Combining ambiguous chemical shift mapping with structure-based backbone and NOE assignment from 15N-NOESY

KAUST Repository

Jang, Richard

2011-01-01

Chemical shift mapping is an important technique in NMRbased drug screening for identifying the atoms of a target protein that potentially bind to a drug molecule upon the molecule\\'s introduction in increasing concentrations. The goal is to obtain a mapping of peaks with known residue assignment from the reference spectrum of the unbound protein to peaks with unknown assignment in the target spectrum of the bound protein. Although a series of perturbed spectra help to trace a path from reference peaks to target peaks, a one-to-one mapping generally is not possible, especially for large proteins, due to errors, such as noise peaks, missing peaks, missing but then reappearing, overlapped, and new peaks not associated with any peaks in the reference. Due to these difficulties, the mapping is typically done manually or semi-automatically. However, automated methods are necessary for high-throughput drug screening. We present PeakWalker, a novel peak walking algorithm for fast-exchange systems that models the errors explicitly and performs many-to-one mapping. On the proteins: hBclXL, UbcH5B, and histone H1, it achieves an average accuracy of over 95% with less than 1.5 residues predicted per target peak. Given these mappings as input, we present PeakAssigner, a novel combined structure-based backbone resonance and NOE assignment algorithm that uses just 15N-NOESY, while avoiding TOCSY experiments and 13C- labeling, to resolve the ambiguities for a one-toone mapping. On the three proteins, it achieves an average accuracy of 94% or better. Copyright © 2011 ACM.

Charge-state dependence of binary-encounter-electron cross sections and peak energies

International Nuclear Information System (INIS)

Hidmi, H.I.; Richard, P.; Sanders, J.M.; Schoene, H.; Giese, J.P.; Lee, D.H.; Zouros, T.J.M.; Varghese, S.L.

1993-01-01

The charge-state dependence of the binary-encounter-electron (BEE) double-differential cross section (DDCS) at 0 degree with respect to the beam direction resulting from collisions of 1 MeV/amu H + , C q+ , N q+ , O q+ , F q+ , Si q+ , and Cl q+ , and 0.5 MeV/amu Cu q+ with H 2 is reported. The data show an enhancement in the BEE DDCS as the charge state of the projectile is decreased, in agreement with the data reported by Richard et al. [J. Phys. B 23, L213 (1990)]. The DDCS enhancement ratios observed for the three-electron isoelectronic sequence C 3+ :C 6+ , N 4+ :N 7+ , O 5+ :O 8+ , and F 6+ :F 9+ are about 1.35, whereas a DDCS enhancement of 3.5 was observed for Cu 4+ . The BEE enhancement with increasing electrons on the projectile has been shown by several authors to be due to the non-Coulomb static potential of the projectile and additionally to the e-e exchange interaction. An impulse-approximation (IA) model fits the shape of the BEE DDCS and predicts a Z p 2 dependence for the bare-ion cross sections. The IA also predicts a binary peak energy that is independent of q and Z p and below the classical value of 4t, where t is the energy of electrons traveling with the projectile velocity. We observed a BEE energy shift ΔE (ΔE=4t-E peak , where E peak is the measured energy at the peak of the binary encounter electrons) that is approximately independent of q for the low-Z p ions, whereas the measured ΔE values for Si, Cl, and Cu were found to be q dependent

Multiscale peak detection in wavelet space.

Science.gov (United States)

Zhang, Zhi-Min; Tong, Xia; Peng, Ying; Ma, Pan; Zhang, Ming-Jin; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

2015-12-07

Accurate peak detection is essential for analyzing high-throughput datasets generated by analytical instruments. Derivatives with noise reduction and matched filtration are frequently used, but they are sensitive to baseline variations, random noise and deviations in the peak shape. A continuous wavelet transform (CWT)-based method is more practical and popular in this situation, which can increase the accuracy and reliability by identifying peaks across scales in wavelet space and implicitly removing noise as well as the baseline. However, its computational load is relatively high and the estimated features of peaks may not be accurate in the case of peaks that are overlapping, dense or weak. In this study, we present multi-scale peak detection (MSPD) by taking full advantage of additional information in wavelet space including ridges, valleys, and zero-crossings. It can achieve a high accuracy by thresholding each detected peak with the maximum of its ridge. It has been comprehensively evaluated with MALDI-TOF spectra in proteomics, the CAMDA 2006 SELDI dataset as well as the Romanian database of Raman spectra, which is particularly suitable for detecting peaks in high-throughput analytical signals. Receiver operating characteristic (ROC) curves show that MSPD can detect more true peaks while keeping the false discovery rate lower than MassSpecWavelet and MALDIquant methods. Superior results in Raman spectra suggest that MSPD seems to be a more universal method for peak detection. MSPD has been designed and implemented efficiently in Python and Cython. It is available as an open source package at .

Automated asteroseismic peak detections

DEFF Research Database (Denmark)

de Montellano, Andres Garcia Saravia Ortiz; Hekker, S.; Themessl, N.

2018-01-01

Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However......, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible...... of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler....

Environmental impacts of public transport. Why peak-period travellers cause a greater environmental burden than off-peak travellers

International Nuclear Information System (INIS)

Rietveld, P.

2002-01-01

Given the difference between peak and off-peak occupancy rates in public transport, emissions per traveller kilometre are lower in the peak than in the off-peak period, whereas the opposite pattern is observed for cars. It is argued that it is much more fruitful to analyse environmental effects in marginal terms. This calls for a careful analysis of capacity management policies of public transport suppliers that are facing increased demand during both peak and off-peak periods. A detailed analysis of capacity management by the Netherlands Railways (NS) revealed that off-peak capacity supply is mainly dictated by the demand levels during the peak period. The analysis included the effects of increased frequency and increased vehicle size on environmental impacts, while environmental economies of vehicle size were also taken into account. The main conclusion is that the marginal environmental burden during the peak hours is much higher than is usually thought, whereas it is almost zero during the off-peak period. This implies a pattern that is the precise opposite of the average environmental burden. Thus, an analysis of environmental effects of public transport based on average performance would yield misleading conclusions [nl

Limited Effects of Set Shifting Training in Healthy Older Adults

Directory of Open Access Journals (Sweden)

Petra Grönholm-Nyman

2017-03-01

Full Text Available Our ability to flexibly shift between tasks or task sets declines in older age. As this decline may have adverse effects on everyday life of elderly people, it is of interest to study whether set shifting ability can be trained, and if training effects generalize to other cognitive tasks. Here, we report a randomized controlled trial where healthy older adults trained set shifting with three different set shifting tasks. The training group (n = 17 performed adaptive set shifting training for 5 weeks with three training sessions a week (45 min/session, while the active control group (n = 16 played three different computer games for the same period. Both groups underwent extensive pre- and post-testing and a 1-year follow-up. Compared to the controls, the training group showed significant improvements on the trained tasks. Evidence for near transfer in the training group was very limited, as it was seen only on overall accuracy on an untrained computerized set shifting task. No far transfer to other cognitive functions was observed. One year later, the training group was still better on the trained tasks but the single near transfer effect had vanished. The results suggest that computerized set shifting training in the elderly shows long-lasting effects on the trained tasks but very little benefit in terms of generalization.

Cement dust exposure and acute lung function: A cross shift study

Directory of Open Access Journals (Sweden)

Moen Bente E

2010-04-01

Full Text Available Abstract Background Few studies have been carried out on acute effects of cement dust exposure. This study is conducted to investigate the associations between current "total" dust exposure and acute respiratory symptoms and respiratory function among cement factory workers. Methods A combined cross-sectional and cross-shift study was conducted in Dire Dawa cement factory in Ethiopia. 40 exposed production workers from the crusher and packing sections and 20 controls from the guards were included. Personal "total" dust was measured in the workers' breathing zone and peak expiratory flow (PEF was measured for all selected workers before and after the shift. When the day shift ended, the acute respiratory symptoms experienced were scored and recorded on a five-point Likert scale using a modified respiratory symptom score questionnaire. Results The highest geometric mean dust exposure was found in the crusher section (38.6 mg/m3 followed by the packing section (18.5 mg/m3 and the guards (0.4 mg/m3. The highest prevalence of respiratory symptoms for the high exposed workers was stuffy nose (85% followed by shortness of breath (47% and "sneezing" (45%. PEF decreased significantly across the shift in the high exposed group. Multiple linear regression showed a significant negative association between the percentage cross-shift change in PEF and total dust exposure. The number of years of work in high-exposure sections and current smoking were also associated with cross-shift decrease in PEF. Conclusions Total cement dust exposure was related to acute respiratory symptoms and acute ventilatory effects. Implementing measures to control dust and providing adequate personal respiratory protective equipment for the production workers are highly recommended.

Experimental investigation on electron cyclotron absorption at down-shifted frequency in the PLT tokamak

International Nuclear Information System (INIS)

Mazzucato, E.; Fidone, I.; Cavallo, A.; von Goeler, S.; Hsuan, H.

1986-05-01

The absorption of 60 GHz electron cyclotron waves, with the extraordinary mode and an oblique angle of propagation, has been investigated in the PLT tokamak in the regime of down-shifted frequencies. The production of energetic electrons, with energies of up to 300 to 400 keV, peaks at values of toroidal field (approx. =29 kG) for which the wave frequency is significantly smaller than the electron cyclotron frequency in the whole plasma region. The observations are consistent with the predictions of the relativistic theory of electron cyclotron damping at down-shifted frequency. Existing rf sources make this process a viable method for assisting the current ramp-up, and for heating the plasma of present large tokamaks

The single-particle density of states, bound states, phase-shift flip, and a resonance in the presence of an Aharonov-Bohm potential

International Nuclear Information System (INIS)

Moroz, A.

1994-01-01

Both the nonrelativistic scattering and the spectrum in the presence of the Aharonov-Bohm potential are analyzed, and the single-particle density of states for different self-adjoint extensions is calculated, which is shown to be a symmetric and periodic function of the flux depending only on the distance from the nearest integer. The Aharonov-Casher theorem on the number of zero modes is corrected for the singular field configuration. The Hall resistivity is calculated in the dilute vortex limit. The magnetic moment coupling and not the spin is shown to be the primary source for the phase-shift flip that may occur even in its absence. The total energy of the system consisting of particles and field is discussed. (author) 65 refs.; 5 figs.; 1 tab

Photoluminescence blue shift of indium phosphide nanowire networks with aluminum oxide coating

International Nuclear Information System (INIS)

Fryauf, David M.; Zhang, Junce; Norris, Kate J.; Diaz Leon, Juan J.; Oye, Michael M.; Kobayashi, Nobuhiko P.; Wei, Min

2014-01-01

This paper describes our finding that optical properties of semiconductor nanowires were modified by depositing a thin layer of metal oxide. Indium phosphide nanowires were grown by metal organic chemical vapor deposition on silicon substrates with gold catalyst resulting in three-dimensional nanowire networks, and optical properties were obtained from the collective nanowire networks. The networks were coated with an aluminum oxide thin film deposited by plasma-enhanced atomic layer deposition. We studied the dependence of the peak wavelength of photoluminescence spectra on the thickness of the oxide coatings. A continuous blue shift in photoluminescence spectra was observed when the thickness of the oxide coating was increased. The observed blue shift is attributed to the Burstein-Moss effect due to increased carrier concentration in the nanowire cores caused by repulsion from intrinsic negative fixed charges located at the inner oxide surface. Samples were further characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and selective area diffractometry to better understand the physical mechanisms for the blue shift. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Photoluminescence blue shift of indium phosphide nanowire networks with aluminum oxide coating

Energy Technology Data Exchange (ETDEWEB)

Fryauf, David M.; Zhang, Junce; Norris, Kate J.; Diaz Leon, Juan J.; Oye, Michael M.; Kobayashi, Nobuhiko P. [Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California, Santa Cruz, CA (United States); Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); NASA Ames Research Center, Moffett Field, CA (United States); Wei, Min [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); School of Micro-Electronics and Solid-Electronics, University of Electronic Science and Technology of China, Chengdu (China)

2014-07-15

This paper describes our finding that optical properties of semiconductor nanowires were modified by depositing a thin layer of metal oxide. Indium phosphide nanowires were grown by metal organic chemical vapor deposition on silicon substrates with gold catalyst resulting in three-dimensional nanowire networks, and optical properties were obtained from the collective nanowire networks. The networks were coated with an aluminum oxide thin film deposited by plasma-enhanced atomic layer deposition. We studied the dependence of the peak wavelength of photoluminescence spectra on the thickness of the oxide coatings. A continuous blue shift in photoluminescence spectra was observed when the thickness of the oxide coating was increased. The observed blue shift is attributed to the Burstein-Moss effect due to increased carrier concentration in the nanowire cores caused by repulsion from intrinsic negative fixed charges located at the inner oxide surface. Samples were further characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and selective area diffractometry to better understand the physical mechanisms for the blue shift. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Red/blue-shift dual-directional regulation of α-(Ca, Sr)2SiO4:Eu(2+) phosphors resulting from the incorporation content of Eu(2+)/Sr(2+) ions.

Science.gov (United States)

Lu, Zhijuan; Mao, Zhiyong; Chen, Jingjing; Wang, Dajian

2015-09-21

In this work, tunable emission from green to red and the inverse tuning from red to green in α-(Ca, Sr)2SiO4:Eu(2+) phosphors were demonstrated magically by varying the incorporation content of Eu(2+) and Sr(2+) ions, respectively. The tunable emission properties and the tuning mechanism of red-shift resulting from the Eu(2+) content as well as that of blue-shift induced by the Sr(2+) content were investigated in detail. As a result of fine-controlling the incorporation content of Eu(2+), the emission peak red-shifts from 541 nm to 640 nm. On the other hand, the emission peak inversely blue-shifts from 640 nm to 546 nm through fine-adjusting the incorporation content of Sr(2+). The excellent tuning characteristics for α-(Ca, Sr)2SiO4:Eu(2+) phosphors presented in this work exhibited their various application prospects in solid-state lighting combining with a blue chip or a near-UV chip.

Effect of Metal Dopant on Ninhydrin—Organic Nonlinear Optical Single Crystals

Directory of Open Access Journals (Sweden)

R. S. Sreenivasan

2013-01-01

Full Text Available In the present work, metal (Cu2+-substituted ninhydrin single crystals were grown by slow evaporation method. The grown crystals have been subjected to single crystal XRD, powder X-ray diffraction, FTIR, dielectric and SHG studies. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in monoclinic system with noncentrosymmetric space group P21 with lattice parameters a=11.28 Å, b=5.98 Å, c=5.71 Å, α=90∘, β=98.57, γ=90∘, and V=381 (Å3, which agrees very well with the reported value. The sharp and strong peaks in the powder X-ray diffraction pattern confirm the good crystallinity of the grown crystals. The presence of dopants marginally altered the lattice parameters without affecting the basic structure of the crystal. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength 314 nm. The vibrational frequencies of various functional groups in the crystals have been derived from FT-IR analysis. Based on the shifts in the vibrations, the presence of copper in the lattice of the grown crystal is clearly established from the pure ninhydrin crystals. Both dielectric constant and dielectric loss decrease with the increase in frequency. The second harmonic generation efficiency was measured by employing powder Kurtz method.

Development of Michelson interferometer based spatial phase-shift digital shearography

Science.gov (United States)

Xie, Xin

Digital shearography is a non-contact, full field, optical measurement method, which has the capability of directly measuring the gradient of deformation. For high measurement sensitivity, phase evaluation method has to be introduced into digital shearography by phase-shift technique. Catalog by phase-shift method, digital phase-shift shearography can be divided into Temporal Phase-Shift Digital Shearography (TPS-DS) and Spatial Phase-Shift Digital Shearography (SPS-DS). TPS-DS is the most widely used phase-shift shearography system, due to its simple algorithm, easy operation and good phase-map quality. However, the application of TPS-DS is only limited in static/step-by-step loading measurement situation, due to its multi-step shifting process. In order to measure the strain under dynamic/continuous loading situation, a SPS-DS system has to be developed. This dissertation aims to develop a series of Michelson Interferometer based SPS-DS measurement methods to achieve the strain measurement by using only a single pair of speckle pattern images. The Michelson Interferometer based SPS-DS systems utilize special designed optical setup to introduce extra carrier frequency into the laser wavefront. The phase information corresponds to the strain field can be separated on the Fourier domain using a Fourier Transform and can further be evaluated with a Windowed Inverse Fourier Transform. With different optical setups and carrier frequency arrangements, the Michelson Interferometer based SPS-DS method is capable to achieve a variety of measurement tasks using only single pair of speckle pattern images. Catalog by the aimed measurand, these capable measurement tasks can be divided into five categories: 1) measurement of out-of-plane strain field with small shearing amount; 2) measurement of relative out-of-plane deformation field with big shearing amount; 3) simultaneous measurement of relative out-of-plane deformation field and deformation gradient field by using multiple

Drivers of peak sales for pharmaceutical brands

NARCIS (Netherlands)

Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

2010-01-01

Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

Paradigm shifts in critical care medicine: the progress we have made.

Science.gov (United States)

Vincent, Jean-Louis; Creteur, Jacques

2015-01-01

There have really been no single, major, advances in critical care medicine since the specialty came into existence. There has, however, been a gradual, continuous improvement in the process of care over the years, which has resulted in improved patient outcomes. Here, we will highlight just a few of the paradigm shifts we have seen in processes of critical care, including the move from small, closed units to larger, more open ICUs; from a paternal "dictatorship" to more "democratic" team-work; from intermittent to continuous, invasive to less-invasive monitoring; from "more" interventions to "less" thus reducing iatrogenicity; from consideration of critical illness as a single event to realization that it is just one part of a trajectory; and from "four walls" to "no walls" as we take intensive care outside the physical ICU. These and other paradigm shifts have resulted in improvements in the whole approach to patient management, leading to more holistic, humane care for patients and their families. As critical care medicine continues to develop, further paradigm shifts in processes of care are inevitable and must be embraced if we are to continue to provide the best possible care for all critically ill patients.

Paradigm shifts in critical care medicine: the progress we have made

Science.gov (United States)

2015-01-01

There have really been no single, major, advances in critical care medicine since the specialty came into existence. There has, however, been a gradual, continuous improvement in the process of care over the years, which has resulted in improved patient outcomes. Here, we will highlight just a few of the paradigm shifts we have seen in processes of critical care, including the move from small, closed units to larger, more open ICUs; from a paternal "dictatorship" to more "democratic" team-work; from intermittent to continuous, invasive to less-invasive monitoring; from "more" interventions to "less" thus reducing iatrogenicity; from consideration of critical illness as a single event to realization that it is just one part of a trajectory; and from "four walls" to "no walls" as we take intensive care outside the physical ICU. These and other paradigm shifts have resulted in improvements in the whole approach to patient management, leading to more holistic, humane care for patients and their families. As critical care medicine continues to develop, further paradigm shifts in processes of care are inevitable and must be embraced if we are to continue to provide the best possible care for all critically ill patients. PMID:26728199

Sensitivity of peak positions to flight-path parameters in a deep-inelastic scattering neutron TOF spectrometer

International Nuclear Information System (INIS)

Gray, E.MacA.; Chatzidimitriou-Dreismann, C.A.; Blach, T.P.

2012-01-01

The effects of small changes in flight-path parameters (primary and secondary flight paths, detector angles), and of displacement of the sample along the beam axis away from its ideal position, are examined for an inelastic time-of-flight (TOF) neutron spectrometer, emphasising the deep-inelastic regime. The aim was to develop a rational basis for deciding what measured shifts in the positions of spectral peaks could be regarded as reliable in the light of the uncertainties in the calibrated flight-path parameters. Uncertainty in the length of the primary or secondary flight path has the least effect on the positions of the peaks of H, D and He, which are dominated by the accuracy of the calibration of the detector angles. This aspect of the calibration of a TOF spectrometer therefore demands close attention to achieve reliable outcomes where the position of the peaks is of significant scientific interest and is discussed in detail. The corresponding sensitivities of the position of peak of the Compton profile, J(y), to flight-path parameters and sample position are also examined, focusing on the comparability across experiments of results for H, D and He. We show that positioning the sample to within a few mm of the ideal position is required to ensure good comparability between experiments if data from detectors at high forward angles are to be reliably interpreted.

Analytic fitting of x- and gamma-ray peaks in Ge and Si(Li) spectroscopy

International Nuclear Information System (INIS)

Campbell, J.L.; Maxwell, J.A.

1984-01-01

A review is presented of current methodology for non-linear least squares fitting of single and multiple peaks, with the emphasis on planar Ge detectors used in the 50-150 keV energy region. The need for new work on Si(Li) detectors at energies 1-40 keV is stressed

Centers responsible for the TL peaks of willemite mineral estimated by EPR analysis

Energy Technology Data Exchange (ETDEWEB)

Gundu Rao, T.K. [Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP 05508-090, São Paulo, SP (Brazil); Cano, Nilo F., E-mail: nilo.cano@unifesp.br [Departamento de Ciências do Mar, Universidade Federal de São Paulo, Rua Doutor Carvalho de Mendonça, 144, CEP 11070-102, Santos, SP (Brazil); Silva-Carrera, Betzabel N.; Ferreira, Reinaldo M. [Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP 05508-090, São Paulo, SP (Brazil); Javier-Ccallata, Henry S., E-mail: henrysjc@gmail.com [Escuela Profesional de Física, Facultad de Ciencias Naturales y Formales, Universidad Nacional de San Agustín (UNSA), Av. Independencia S/N, Arequipa (Peru); Watanabe, Shigueo, E-mail: watanabe@if.usp.br [Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP 05508-090, São Paulo, SP (Brazil)

2016-09-15

The mineral willemite (Zn{sub 2}SiO{sub 4}) exhibits five thermoluminescence (TL) peaks approximately at 160, 225, 260, 310 and 400 °C. Electron paramagnetic resonance (EPR) studies were carried out to study the defect centers induced in the mineral by gamma irradiation and also to identify the centers responsible for the TL process. Room temperature EPR spectrum of irradiated mineral is a superposition of at least four distinct centers. One of the centers (center I) with an isotropic g factor 2.0114 is attributable to an intrinsic O{sup −} type center and the center correlates with the TL peak at 160 °C. Center II exhibiting hyperfine lines is also tentatively assigned to an O{sup −} ion and is related to the low temperature TL peak at 160 °C. Center III is characterized by an axially symmetric g-tensor with principal values g{sub ||}=2.0451 and g{sub ⊥}=2.011 and is identified as an O{sub 2}{sup −} ion. This center appears to be related to 160, 225 and 260 °C TL peaks. Center IV with principal g-values g{sub ||}=2.0025 and g{sub ⊥}=2.0088 is attributed to an F{sup +}-type center (singly ionized oxygen vacancy) and is the likely recombination center for TL peaks between 160 and 310 °C.

Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

Directory of Open Access Journals (Sweden)

Gabriele Grandi

2013-08-01

Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

Gold nanoshell photomodification under a single-nanosecond laser pulse accompanied by color-shifting and bubble formation phenomena

International Nuclear Information System (INIS)

Akchurin, Garif; Khlebtsov, Boris; Akchurin, Georgy; Tuchin, Valery; Zharov, Vladimir; Khlebtsov, Nikolai

2008-01-01

Laser-nanoparticle interaction is crucial for biomedical applications of lasers and nanotechnology to the treatment of cancer or pathogenic microorganisms. We report on the first observation of laser-induced coloring of gold nanoshell solution after a one nanosecond pulse and an unprecedentedly low bubble formation (as the main mechanism of cancer cell killing) threshold at a laser fluence of about 4 mJ cm -2 , which is safe for normal tissue. Specifically, silica/gold nanoshell (140/15 nm) suspensions were irradiated with a single 4 ns (1064 nm) or 8 ns (900 nm) laser pulse at fluences ranging from 0.1 mJ cm -2 to 50 J cm -2 . Solution red coloring was observed by the naked eye confirmed by blue-shifting of the absorption spectrum maximum from the initial 900 nm for nanoshells to 530 nm for conventional colloidal gold nanospheres. TEM images revealed significant photomodification of nanoparticles including complete fragmentation of gold shells, changes in silica core structure, formation of small 20-30 nm isolated spherical gold nanoparticles, gold nanoshells with central holes, and large and small spherical gold particles attached to a silica core. The time-resolved monitoring of bubble formation phenomena with the photothermal (PT) thermolens technique demonstrated that after application of a single 8 ns pulse at fluences 5-10 mJ cm -2 and higher the next pulse did not produce any PT response, indicating a dramatic decrease in absorption because of gold shell modification. We also observed a dependence of the bubble expansion time on the laser energy with unusually very fast PT signal rising (∼3.5 ns scale at 0.2 J cm -2 ). Application of the observed phenomena to medical applications is discussed, including a simple visual color test for laser-nanoparticle interaction

Working the night shift causes increased vascular stress and delayed recovery in young women.

Science.gov (United States)

Lo, Shih-Hsiang; Lin, Lian-Yu; Hwang, Jing-Shiang; Chang, Yu-Yin; Liau, Chiau-Suong; Wang, Jung-Der

2010-08-01

Shiftwork has been associated with elevated blood pressure (BP) and decreased heart-rate variability (HRV), factors that may increase the long-term risk of cardiovascular-related mortality and morbidity. This study explored the effect of shiftwork on dynamic changes in autonomic control of HRV (cardiac stress), systolic BP and diastolic BP, i.e., SBP and DBP (vascular stress), and recovery in the same subjects working different shifts. By studying the same subjects, the authors could reduce the effect of possible contribution of between-subject variation from genetic predisposition and environmental factors. The authors recruited 16 young female nurses working rotating shifts--day (08:00-16:00 h), evening (16:00-00:00 h), and night (00:00-08:00 h)--and 6 others working the regular day shift. Each nurse received simultaneous and repeated 48-h ambulatory electrocardiography and BP monitoring during their work day and the following off-duty day. Using a linear mixed-effect model to adjust for day shift, the results of the repeated-measurements and self-comparisons found significant shift differences in vascular stress. While working the night shift, the nurses showed significant increases in vascular stress, with increased SBP of 9.7 mm Hg. The changes of SBP and DBP seemed to peak during waking time at the same time on the day off as they did on the working day. Whereas HRV profiles usually returned to baseline level after each shift, the SBP and DBP of night-shift workers did not completely return to baseline levels the following off-duty day (p night shift, they do not completely recover from increases in vascular stress on that day.

Parameter design and performance analysis of shift actuator for a two-speed automatic mechanical transmission for pure electric vehicles

Directory of Open Access Journals (Sweden)

Jianjun Hu

2016-08-01

Full Text Available Recent developments of pure electric vehicles have shown that pure electric vehicles equipped with two-speed or multi-speed gearbox possess higher energy efficiency by ensuring the drive motor operates at its peak performance range. This article presents the design, analysis, and control of a two-speed automatic mechanical transmission for pure electric vehicles. The shift actuator is based on a motor-controlled camshaft where a special geometric groove is machined, and the camshaft realizes the axial positions of the synchronizer sleeve for gear engaging, disengaging, and speed control of the drive motor. Based on the force analysis of shift process, the parameters of shift actuator and shift motor are designed. The drive motor’s torque control strategy before shifting, speed governing control strategy before engaging, shift actuator’s control strategy during gear engaging, and drive motor’s torque recovery strategy after shift process are proposed and implemented with a prototype. To validate the performance of the two-speed gearbox, a test bed was developed based on dSPACE that emulates various operation conditions. The experimental results indicate that the shift process with the proposed shift actuator and control strategy could be accomplished within 1 s under various operation conditions, with shift smoothness up to passenger car standard.

How to use your peak flow meter

Science.gov (United States)

... meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

The Impact of the Twin Peaks Model on the Insurance Industry

Directory of Open Access Journals (Sweden)

Daleen Millard

2017-02-01

Full Text Available Financial regulation in South Africa changes constantly. In the quest to find the ideal regulatory framework for optimal consumer protection, rules change all the time and international trends have an important influence on lawmakers nationally. The Financial Sector Regulation Bill, also known as the "Twin Peaks" Bill, is the latest invention from the table of the legislature, and some expect this Bill to have far-reaching consequences for the financial services industry. The question is, of course, whether the current dispensation will change so quickly and so dramatically that it will literally be the end of the world as we know it or whether there will be a gradual shift in emphasis away from the so-called silo regulatory approach to an approach that distinguishes between prudential regulation on the one hand and market conduct regulation on the other. A further question is whether insurance as a financial service will change dramatically in the light of the expected twin peak dispensation. The purpose of this paper is to discuss the implications of the FSR Bill for the insurance industry. Instead of analysing the Bill feature for feature, the method that will be used in this enquiry is to identify trends and issues from 2014 and to discuss whether the Twin Peaks model, once implemented, can successfully eradicate similar problems in future. The impact of Twin Peaks will of course have to be tested, but at this point in time it may be very useful to take an educated guess by using recent cases as examples. Recent cases before the courts, the Enforcement Committee and the FAIS Ombud will be discussed not only as examples of the most prevalent issues of the past year or so, but also as examples of how consumer issues and systemic risks are currently being dealt with and how this may change with the implementation of the FSR Bill.

Measurements of Nascent Soot Using a Cavity Attenauted Phase Shift (CAPS)-based Single Scattering Albedo Monitor

Science.gov (United States)

Freedman, A.; Onasch, T. B.; Renbaum-Wollf, L.; Lambe, A. T.; Davidovits, P.; Kebabian, P. L.

2015-12-01

Accurate, as compared to precise, measurement of aerosol absorption has always posed a significant problem for the particle radiative properties community. Filter-based instruments do not actually measure absorption but rather light transmission through the filter; absorption must be derived from this data using multiple corrections. The potential for matrix-induced effects is also great for organic-laden aerosols. The introduction of true in situ measurement instruments using photoacoustic or photothermal interferometric techniques represents a significant advance in the state-of-the-art. However, measurement artifacts caused by changes in humidity still represent a significant hurdle as does the lack of a good calibration standard at most measurement wavelengths. And, in the absence of any particle-based absorption standard, there is no way to demonstrate any real level of accuracy. We, along with others, have proposed that under the circumstance of low single scattering albedo (SSA), absorption is best determined by difference using measurement of total extinction and scattering. We discuss a robust, compact, field deployable instrument (the CAPS PMssa) that simultaneously measures airborne particle light extinction and scattering coefficients and thus the single scattering albedo (SSA) on the same sample volume. The extinction measurement is based on cavity attenuated phase shift (CAPS) techniques as employed in the CAPS PMex particle extinction monitor; scattering is measured using integrating nephelometry by incorporating a Lambertian integrating sphere within the sample cell. The scattering measurement is calibrated using the extinction measurement of non-absorbing particles. For small particles and low SSA, absorption can be measured with an accuracy of 6-8% at absorption levels as low as a few Mm-1. We present new results of the measurement of the mass absorption coefficient (MAC) of soot generated by an inverted methane diffusion flame at 630 nm. A value

A novel fast phase correlation algorithm for peak wavelength detection of Fiber Bragg Grating sensors.

Science.gov (United States)

Lamberti, A; Vanlanduit, S; De Pauw, B; Berghmans, F

2014-03-24

Fiber Bragg Gratings (FBGs) can be used as sensors for strain, temperature and pressure measurements. For this purpose, the ability to determine the Bragg peak wavelength with adequate wavelength resolution and accuracy is essential. However, conventional peak detection techniques, such as the maximum detection algorithm, can yield inaccurate and imprecise results, especially when the Signal to Noise Ratio (SNR) and the wavelength resolution are poor. Other techniques, such as the cross-correlation demodulation algorithm are more precise and accurate but require a considerable higher computational effort. To overcome these problems, we developed a novel fast phase correlation (FPC) peak detection algorithm, which computes the wavelength shift in the reflected spectrum of a FBG sensor. This paper analyzes the performance of the FPC algorithm for different values of the SNR and wavelength resolution. Using simulations and experiments, we compared the FPC with the maximum detection and cross-correlation algorithms. The FPC method demonstrated a detection precision and accuracy comparable with those of cross-correlation demodulation and considerably higher than those obtained with the maximum detection technique. Additionally, FPC showed to be about 50 times faster than the cross-correlation. It is therefore a promising tool for future implementation in real-time systems or in embedded hardware intended for FBG sensor interrogation.

Resolution of NMR chemical shift images into real and imaginary components

International Nuclear Information System (INIS)

Yamamoto, E.; Kohno, H.

1986-01-01

Fast chemical shift imaging of two-line materials is described using a modified spin-echo sequence. The method resolves the two chemical shift images into real and imaginary components representing the reconstructed image. The measuring time is reduced to half of that for the conventional method proposed by Dixon et al, and quantitative evaluation of the images becomes possible. Reference material with a single resonant line is used to eliminate the phase error caused by static field inhomogeneity and the inherent apparatus offset phase. Experiments are conducted using acetone and benzene with a medium-bore superconductive magnet operating at 0.5T. From these experiments, two chemical shift images are obtained. These images are then superimposed to produce a conventional density image. (author)

NMR-based Enantiodifferentiation of Chiral trans-2-Phenylcyclopropane Derivatives Using a Chiral Lanthanide Shift Reagent

International Nuclear Information System (INIS)

Cho, Nam Sook; Kim, Hyun Sook; Song, Mi Sook

2011-01-01

In contrast with optical methods, there is no need to characterize the pure enantiomers. Instead, the NMR method makes use of chiral reagents that convert a mixture of enantiomers into a mixture of diastereomeric complexes. Integration of the resulting NMR spectra yields a direct measurement of enantiomeric purity as long as there is a sufficiently large difference between the chemical shifts of the two diastereoisomeric complexes to produce baseline-resolved peaks. Absolute enantiomeric configurations can also be determined using this method. Chiral lanthanide shift reagents have been used since the 1970s to form addition complexes with various compounds through interactions with electron donor sites. Lanthanide-induced, pseudo-contact shifts (LIS) are a function of the distance, r, between the nuclei under observation and the lanthanide center, and the angle, θ, between the line connecting the metal ion with the observed nucleus and the line representing the CLSR magnetic axis

High-speed Light Peak optical link for high energy applications

Energy Technology Data Exchange (ETDEWEB)

Chang, F.X. [Academia Sinica, Taipei, Taiwan (China); Chiang, F. [FOCI Fiber Optic Comm., Inc., Hsinchu, Taiwan (China); Deng, B. [Hubei Polytechnic University, Huangshi, Hubei (China); Southern Methodist University, Dallas, TX (United States); Hou, J. [FOCI Fiber Optic Comm., Inc., Hsinchu, Taiwan (China); Hou, S., E-mail: suen@gate.sinica.edu.tw [Academia Sinica, Taipei, Taiwan (China); Liu, C.; Liu, T. [Southern Methodist University, Dallas, TX (United States); Teng, P.K. [Academia Sinica, Taipei, Taiwan (China); Wang, C.H. [National United University, Miaoli, Taiwan (China); Xu, T. [Shandong University, Ji' nan (China); Southern Methodist University, Dallas, TX (United States); Ye, J. [Southern Methodist University, Dallas, TX (United States)

2014-11-21

Optical links provide high speed data transmission with low mass fibers favorable for applications in high energy experiments. We report investigation of a compact Light Peak optical engine designed for data transmission at 4.8 Gbps. The module is assembled with bare die VCSEL, PIN diodes and a control IC aligned within a prism receptacle for light coupling to fiber ferrule. Radiation damage in the receptacle was examined with {sup 60}Co gamma ray. Radiation induced single event effects in the optical engine were studied with protons, neutrons and X-ray tests.