Search for long lived charged massive particles in pp collisions at s-hat = 1.8TeV

We report a search for the production of long-lived charged massive particles in a data sample of 90   pb-1 of √s=1.8   TeV pp̅ collisions recorded by the Collider Detector at Fermilab. The search uses the muonlike penetration and anomalously high ionization energy loss signature expected for such a particle to discriminate it from backgrounds. The data are found to agree with background expectations, and cross section limits of O(1) pb are derived using two reference models, a stable quark and a stable scalar lepton

Pump-probe differencing technique for cavity-enhanced, noise-canceling saturation laser spectroscopy

We present an experimental technique enabling mechanical-noise free, cavity-enhanced frequency measurements of an atomic transition and its hyperfine structure. We employ the 532nm frequency doubled output from a Nd:YAG laser and an iodine vapour cell. The cell is placed in a traveling-wave Fabry-Perot interferometer (FPI) with counter-propagating pump and probe beams. The FPI is locked using the Pound-Drever-Hall (PDH) technique. Mechanical noise is rejected by differencing pump and probe signals. In addition, this differenced error signal gives a sensitive measure of differential non-linearity within the FPI.Comment: 3 pages, 5 figures, submitted to Optics Letter

Laser Frequency Stabilization for LISA

This research focuses on laser ranging developments for LISA (Laser Interferometer Space Antenna), a planned NASA-ESA gravitational wave detector in space. LISA will utilize precision laser interferometry to track the changes in separation between three satellites orbiting 5 million kilometers apart. Specifically, our goal is to investigate options for laser frequency stabilization. Previous research has shown that an optical cavity system can meet LISA\u27s stability requirements, but these units are large and heavy, adding cost to the implementation. A heterodyne Mach-Zehnder interferometer could be integrated onto LISA’s existing optical bench, greatly reducing the weight, provided the interferometer meets the stability requirements. On this poster, we describe a performance comparison between an optical cavity and a Mach-Zehnder interferometer, by measuring the relative phase of stabilized lasers from the two systems. This project\u27s results will determine whether a heterodyne Mach-Zehnder is suitable for LISA

The Efficiency of a Two-Stage Reluctance Accelerator through Pulse Shaping

An investigation considering the efficiency gains of electrical pulse-shaping for a two-stage reluctance accelerator system has been undertaken. An optimum gross efficiency of (1.36 ± 0.02)% was achieved, amounting to an increase of (290 ± 20)% relative to the performance of an equivalent single-stage accelerator. The performance increase due to pulse-shaping for a two-stage setup was found to surpass that achieved for this single-stage setup in terms of both efficiency and velocity. This investigation highlights the potential of pulse-shaping methods to increase the feasibility and flexibility of electrical acceleration for a variety of practical applications. The intention of this paper was to exhibit the potential of reluctance acceleration technology in multi-stage, initially by using a two-stage system. Possible avenues for further investigation are proposed, to build upon the results of this study

Preclinical Evaluation of Novel All-in-one Formulations of 5-Fluorouracil and Folinic Acid with Reduced Toxicity Profiles - Supplementary Data

Objectives: 5-Fluorouracil (5-FU) in combination with its synergistic biomodulator folinic acid maintains a pivotal position in cancer chemotherapy. However, clinical limitations persist with the administration of these drugs in combination including phlebitis and catheter blockages, which are associated with reduced efficacy and/or quality of life for patients. We have previously reported novel all-in-one, pH neutral, parenteral 5-FU and folinic acid formulations (termed Fluorodex) incorporating beta-cyclodextrins. Fluorodex maintains potency while overcoming the accepted incompatibility of 5-FU and folinic acid.Methods: We performed toxicological, pharmacokinetic and biodistribution, and efficacy evaluations of Fluorodex compared to 5-FU:folinic acid using several administration routes and schedules in two rodent models. These were compared to dose-matched sequential administration of 5-FU:folinic acid.Results: Fluorodex showed bioequivalence to 5-FU:folinic acid as assessed by tissue distribution and pharmacokinetics of 5-FU, but was generally better tolerated as determined by weight loss, hematological and other clinical parameters. Compared to 5-FU:folinic acid, Fluorodex was also associated with reduced phlebitis using a rabbit ear vein model. Furthermore, equivalent to enhanced efficacy of Fluorodex compared to 5-FU:folinic acid against human carcinoma tumour models in mice was observed.Conclusions: These novel all-in-one formulations represent a superior injectable form of 5- FU that allows co-delivery of folinic acid. This should translate to improved patient tolerability with potential for enhanced efficacy

Progress in Interferometry for LISA at JPL

Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of Time Delay Interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.Comment: 11 pages, 9 figures, LISA 8 Symposium, Stanford University, 201

Testing and Modeling Ethernet Switches and Networks for Use in ATLAS High-level Triggers

The ATLAS second level trigger will use a multi-layered LAN network to transfer 5 Gbyte/s detector data from ~1500 buffers to a few hundred processors. A model of the network has been constructed to evaluate its performance. A key component of the network model is a model of an individual switch, reproducing the behavior measured in real devices. A small number of measurable parameters are used to model a variety of commercial Ethernet switches. Using parameters measured on real devices, the impact on the overall network performance is modeled. In the Atlas context, both 100 Mbit and Gigabit Ethernet links are required. A system is described which is capable of characterizing the behavior of commercial switches with the required number of nodes under traffic conditions resembling those to be encountered in the Atlas experiment. Fast Ethernet traffic is provided by a high density, custom built tester based on FPGAs, programmed in Handel-C and VHDL, while the Gigabit Ethernet traffic is generated using Alteon NICs with custom firmware. The system is currently being deployed with 32 100Mbit ports and 16 Gigabit ports, and will be expanded to ~256 nodes of 100 Mbit and ~50 GBE nodes

Practical considerations for assessing pulmonary gas exchange and ventilation during flume swimming using the MetaSwim metabolic cart

The MetaSwim (MS) metabolic cart can assess pulmonary gas exchange and ventilation in aquatic environments. The aims of this study were: 1) to determine the agreement between minute ventilation (V̇E), pulmonary oxygen uptake (V̇O2) and carbon dioxide output (V̇CO2) using the MS and Douglas Bag (DB) methods during flume swimming; 2) to assess the repeatability of these and other MS derived parameters. Sixteen trained swimmers completed a combined incremental and supramaximal verification cardiopulmonary swimming test to determine maximal V̇O2, two progressive intensity swimming tests during which MS and DB measurements were made (agreement protocol), and/or three-four constant velocity submaximal swimming tests during which only the MS was used (repeatability protocol). Agreement was determined using limits of agreement (LoA), bias, random error and 95% confidence intervals with systematic bias assessed using paired samples t-tests. Within-trial and between trial repeatability were determined using the coefficient of variation (CV) and the repeatability coefficient (CR). Where data were heteroscedastic, LoA and CR were log-transformed, anti-logged and displayed as ratios. MS underestimated peak V̇O2 and V̇CO2 (<0.39 L.min-1) and V̇E (9.08 L.min-1), while submaximal values varied between 2-5% for CV and ±1.09-1.22 for ratio CR. The test re-test CV during constant velocity swimming for V̇E, tidal volume, breathing frequency, V̇O2, V̇CO2, and end-tidal pressures of O2 and CO2 was < 9% (ratio CR of ±1.09-1.34). Thus, the MS and DB cannot be used interchangeably. Whether the MS is suitable for evaluating ventilatory and pulmonary responses in swimming will depend upon the size of effect required

Analytical method development for tritium in tree transpirate from the little forest burial ground.

The Little Forest Burial Ground (LFBG) is a near-surface low-level nuclear waste repository located within the buffer zone surrounding the Lucas Heights Research Laboratories of ANSTO (Figure 1). Tritium (3H, ‘T’), as tritiated water (HTO), was one of the radioactive substances placed into the trenches located within the LFBG (Isaacs and Mears, 1977). This material will behave conservatively in regard to any seepage from the site of deposition. As such, it should be a good indicator of groundwater movement at the site. Water is a vital requirement of plants. Hence, it was proposed that samples from herbs and trees may be useful to assess the biologically available HTO and also provide an indication of a potential exposure for environmental dose assessment, not only for 3H but also for the other radionuclides potentially migrating with the water from the trenches. As part of the initial draft plan for a vegetation survey in the LFBG (Twining and Creighton, 2007) the following two null hypotheses were established: H0a that there is no significantly higher concentration of specific contaminants in foliage of trees growing over, or adjacent to, the pits than there is in the foliage of the same species growing away from the pits; H0b that there is no correlation between contaminant levels in the seepage plume and surface vegetation. These hypotheses are to be tested using the acquired data. However, as part of the process of applying HTO in transpirate as a monitoring tool, some method development has been required. This report covers all aspects of that development and provides a recommended approach to acquiring such data and recording the information