Heavy ion injector for the CERN Linac 1

An injector system has been designed to provide a fully stripped oxygen beam for acceleration in the CERN PS complex. An ECR source will provide an O/sup 6/+ beam to a heavy ion RFQ accelerator. The beam from the RFQ will be further accelerated by the CERN Linac 1 (Old Linac) in the 2 ..beta.. lambda-mode to an energy of 12.5 MeV/u at which point it will be fully stripped for subsequent acceleration in the CERN synchrotrons. The specifications of the new equipment and modifications to the existing linear accelerator are described

Attribution of divergent northern vegetation growth responses to lengthening non-frozen seasons using satellite optical-NIR and microwave remote sensing

The non-frozen (NF) season duration strongly influences the northern carbon cycle where frozen (FR) temperatures are a major constraint to biological processes. The landscape freeze-thaw (FT) signal from satellite microwave remote sensing provides a surrogate measure of FR temperature constraints to ecosystem productivity, trace gas exchange, and surface water mobility. We analysed a new global satellite data record of daily landscape FT dynamics derived from temporal classification of overlapping SMMR and SSM/I 37 GHz frequency brightness temperatures (Tb). The FT record was used to quantify regional patterns, annual variability, and trends in the NF season over northern (≥45°N) vegetated land areas. The ecological significance of these changes was evaluated against satellite normalized difference vegetation index (NDVI) anomalies, estimated moisture and temperature constraints to productivity determined from meteorological reanalysis, and atmospheric CO2 records. The FT record shows a lengthening (2.4 days decade-1; p < 0.005) mean annual NF season trend (1979-2010) for the high northern latitudes that is 26% larger than the Northern Hemisphere trend. The NDVI summer growth response to these changes is spatially complex and coincides with local dominance of cold temperature or moisture constraints to productivity. Longer NF seasons are predominantly enhancing productivity in cold temperature-constrained areas, whereas these effects are reduced or reversed in more moisture-constrained areas. Longer NF seasons also increase the atmospheric CO2 seasonal amplitude by enhancing both regional carbon uptake and emissions. We find that cold temperature constraints to northern growing seasons are relaxing, whereas potential benefits for productivity and carbon sink activity are becoming more dependent on the terrestrial water balance and supply of plant-available moisture needed to meet additional water use demands under a warming climate. © 2014 Taylor & Francis

Hierarchical structure of cascade of primary and secondary periodicities in Fourier power spectrum of alphoid higher order repeats

<p>Abstract</p> <p>Background</p> <p>Identification of approximate tandem repeats is an important task of broad significance and still remains a challenging problem of computational genomics. Often there is no single best approach to periodicity detection and a combination of different methods may improve the prediction accuracy. Discrete Fourier transform (DFT) has been extensively used to study primary periodicities in DNA sequences. Here we investigate the application of DFT method to identify and study alphoid higher order repeats.</p> <p>Results</p> <p>We used method based on DFT with mapping of symbolic into numerical sequence to identify and study alphoid higher order repeats (HOR). For HORs the power spectrum shows equidistant frequency pattern, with characteristic two-level hierarchical organization as signature of HOR. Our case study was the 16 mer HOR tandem in AC017075.8 from human chromosome 7. Very long array of equidistant peaks at multiple frequencies (more than a thousand higher harmonics) is based on fundamental frequency of 16 mer HOR. Pronounced subset of equidistant peaks is based on multiples of the fundamental HOR frequency (multiplication factor <it>n </it>for <it>n</it>mer) and higher harmonics. In general, <it>n</it>mer HOR-pattern contains equidistant secondary periodicity peaks, having a pronounced subset of equidistant primary periodicity peaks. This hierarchical pattern as signature for HOR detection is robust with respect to monomer insertions and deletions, random sequence insertions etc. For a monomeric alphoid sequence only primary periodicity peaks are present. The 1/<it>f</it>^{<it>β </it>}– noise and periodicity three pattern are missing from power spectra in alphoid regions, in accordance with expectations.</p> <p>Conclusion</p> <p>DFT provides a robust detection method for higher order periodicity. Easily recognizable HOR power spectrum is characterized by hierarchical two-level equidistant pattern: higher harmonics of the fundamental HOR-frequency (secondary periodicity) and a subset of pronounced peaks corresponding to constituent monomers (primary periodicity). The number of lower frequency peaks (secondary periodicity) below the frequency of the first primary periodicity peak reveals the size of <it>n</it>mer HOR, i.e., the number <it>n </it>of monomers contained in consensus HOR.</p

A Climate Record of Enhanced Spatial Resolution Microwave Radiometer Data

Operational satellite radiometers, such SMMR, SSM/I, SSMIS, and AMSR-E, provide a multi-decadal time series of observations of the globe that can support studies of climate change. Unfortunately, spatial resolution and sampling characteristics differ between sensors, which complicate compiling a single climate record. Resolution concerns can be ameliorated by reconstructing radiometer brightness temperature measurement (Tb) data onto daily-averaged compatible grids. We consider and contrast two widely used methods for image reconstruction: a radiometer version of the scatterometer image reconstruction (SIR) algorithm and Backus-Gilbert (BG). Both require the spatial response function (antenna gain pattern) and the sampling geometry. We discuss considerations for an optimum gridding scheme based on the EASE-Grid 2.0 map projection. The EASE-Grid 2.0 simplifies the application of the Tb images in derived products since the reconstruction for each radiometer channel is implement on the same grid. This has the effect of optimally interpolating low-resolution measurements to locations of the highest resolution measurements. By employing reconstruction techniques rather than traditional “drop in the bucket” (dib) gridding, the effective resolution of the images is spatially enhanced compared to dib images, at the expense of additional computation required for the reconstruction processing. We evaluate the sensitivity of the radiometric accuracy of the resulting Tb images to uncertainties in the antenna gain pattern as well as variations in local-time-of-day. We briefly consider a number of applications of reconstructed Tb images. As part of the NASA-MEASUREs project “An improved, enhanced-resolution, gridded passive microwave ESDR for monitoring cryospheric and hydrologic time series” we are processing all available satellite radiometer data to generate a consistently calibrated and processed time series of gridded images spanning from the 1970’s to the present that will be available from the National Snow and Ice Data Center starting later this year

Attempt on estimation of total volatile organic compounds emitted from car interior materials changes : the effect of temperature

W artykule omówiona została próba oszacowania całkowitej ilości lotnych substancji organicznych emitowanych z elementów wyposażenia kabiny w oparciu o wielomiany I i II stopnia. Rzeczywiste zmiany stężenia wytypowanych substancji emitowanych z materiałów w zależności od temperatury zostały przybliżone równaniami wielomianów. Wielomiany po zsumowaniu pozwoliły na oszacowanie wartości całkowitego stężenia substancji organicznych (CLZO) emitowanych z danego materiału. Stwierdzono, że oszacowane wartości CLZO są bardzo zbliżone do wartości rzeczywistych w przypadku wydzielania LZO w temperaturze 50 i 65 ºC. W przypadku niższych temperatur różnice między wartościami oszacowanymi a rzeczywistymi różniły się znacznie bardziej.Paper discussed the attempt on estimation of total volatile organic compounds emitted form car cabin interior materials based on polynomial of degree 1 and 2. Real changes in selected compounds concentrations were approximated by polynomials. These polynomials after summing allowed approximation of total volatile organic compounds concentration (TVOC) emitted from matrial. It was stated that the approximated TVOC values were very close to the actual value for the release of VOCs at 50 ºC and 65 ºC. At lower temperatures the difference between the estimated and actual value differ more significantly

On-line velocity measurements using phase probes at the SuperHILAC

Phase probes have been placed in several external beam lines at the SuperHILAC to provide velocity measurements independent of the type of particle being accelerated. The system uses three probes in each line to obtain accurate velocity measurements at all beam energies. Automatic gain control and signal analysis are performed so that the energy/nucleon along with a representative probe signal are displayed on an oscilloscope every eight seconds. The system is accurate to within about +-0.25%, and has provisions for on-line calibration tests. The phase probes thus provide a velocity measurement independent of the mass defect associated with the use of crystal detectors, which can become significant for heavy elements. 1 ref., 3 figs

Pulsers for the induction linac experiment, MBE-4

The MBE-4 proof-of-principle experiment uses an induction linac to accelerate four Cs+ beams from injection at 200 kV to almost 1MV. When completed in the summer of 1987 it will be 17.2 meters long and have 24 acceleration gaps and 6 diagnostic gaps. Careful tailoring of the accelerating voltage waveforms at each gap is required to accelerate the beam, amplify the current and provide longitudinal focusing. The ideal voltage waveforms required at the first 4 gaps are almost triangular with an amplitude of about 20 kV and an approximate width of 3 ..mu..sec, becoming flatter and shorter with an amplitude of 30 kV at subsequent gaps as the beam current increases and the pulse width narrows. These waveforms (1) are shown in Fig. 1. Pulser voltage waveforms at each gap are adjusted in both amplitude and firing time in conjunction with beam experiments to determine the required voltage waveforms of the subsequent pulsers. Existing cores and previous experience with thyratron pulsers provided the basis for the pulsers for the first half of the machine. During this fabrication period, additional cores and spark gap pulsers capable of generating higher voltages than the thyratron pulsers became available and a combination of both types of pulser will be used to complete the apparatus